1
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Zhou Y, Leng J, Wang K, Gao F, Xu G, Liu H, Ma RL, Cao G, Zhang J, Guo GC, Hu X, Li HO, Guo GP. Quantum Interference and Coherent Population Trapping in a Double Quantum Dot. NANO LETTERS 2024; 24:10040-10046. [PMID: 39133069 DOI: 10.1021/acs.nanolett.4c01781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/13/2024]
Abstract
Quantum interference is a natural consequence of wave-particle duality in quantum mechanics, and is widely observed at the atomic scale. One interesting manifestation of quantum interference is coherent population trapping (CPT), first proposed in three-level driven atomic systems and observed in quantum optical experiments. Here, we demonstrate CPT in a gate-defined semiconductor double quantum dot (DQD), with some unique twists as compared to the atomic systems. Specifically, we observe CPT in both driven and nondriven situations. We further show that CPT in a driven DQD could be used to generate adiabatic state transfer. Moreover, our experiment reveals a nontrivial modulation to the CPT caused by the longitudinal driving field, yielding an odd-even effect and a tunable CPT. Our results broaden the field of CPT, and open up the possibility of quantum simulation and quantum computation based on adiabatic passage in quantum dot systems.
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Affiliation(s)
- Yuan Zhou
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center For Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Jin Leng
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center For Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Ke Wang
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center For Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Fei Gao
- Institute of Physics and CAS Center for Excellence in Topological Quantum Computation, Chinese Academy of Sciences, Beijing 100190, China
| | - Gang Xu
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center For Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - He Liu
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center For Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Rong-Long Ma
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center For Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Gang Cao
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center For Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
- Hefei National Laboratory, Hefei 230088, China
| | - Jianjun Zhang
- Institute of Physics and CAS Center for Excellence in Topological Quantum Computation, Chinese Academy of Sciences, Beijing 100190, China
- Hefei National Laboratory, Hefei 230088, China
| | - Guang-Can Guo
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center For Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
- Hefei National Laboratory, Hefei 230088, China
| | - Xuedong Hu
- Department of Physics, University at Buffalo, SUNY, Buffalo, New York 14260, United States
| | - Hai-Ou Li
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center For Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
- Hefei National Laboratory, Hefei 230088, China
| | - Guo-Ping Guo
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center For Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
- Hefei National Laboratory, Hefei 230088, China
- Origin Quantum Computing Company Limited, Hefei, Anhui 230026, China
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2
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Severin B, Lennon DT, Camenzind LC, Vigneau F, Fedele F, Jirovec D, Ballabio A, Chrastina D, Isella G, de Kruijf M, Carballido MJ, Svab S, Kuhlmann AV, Geyer S, Froning FNM, Moon H, Osborne MA, Sejdinovic D, Katsaros G, Zumbühl DM, Briggs GAD, Ares N. Cross-architecture tuning of silicon and SiGe-based quantum devices using machine learning. Sci Rep 2024; 14:17281. [PMID: 39068242 PMCID: PMC11283483 DOI: 10.1038/s41598-024-67787-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 07/16/2024] [Indexed: 07/30/2024] Open
Abstract
The potential of Si and SiGe-based devices for the scaling of quantum circuits is tainted by device variability. Each device needs to be tuned to operation conditions and each device realisation requires a different tuning protocol. We demonstrate that it is possible to automate the tuning of a 4-gate Si FinFET, a 5-gate GeSi nanowire and a 7-gate Ge/SiGe heterostructure double quantum dot device from scratch with the same algorithm. We achieve tuning times of 30, 10, and 92 min, respectively. The algorithm also provides insight into the parameter space landscape for each of these devices, allowing for the characterization of the regions where double quantum dot regimes are found. These results show that overarching solutions for the tuning of quantum devices are enabled by machine learning.
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Affiliation(s)
- B Severin
- Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH, UK
| | - D T Lennon
- Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH, UK
| | - L C Camenzind
- Department of Physics, University of Basel, Basel, 4056, Switzerland
| | - F Vigneau
- Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH, UK
| | - F Fedele
- Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH, UK
| | - D Jirovec
- Institute of Science and Technology Austria, Am Campus 1, Klosterneuburg, 3400, Austria
| | - A Ballabio
- L-NESS, Dipartimento di Fisica, Politecnico di Milano, Polo di Como, ViaAnzani 42, Como, 22100, Italy
| | - D Chrastina
- L-NESS, Dipartimento di Fisica, Politecnico di Milano, Polo di Como, ViaAnzani 42, Como, 22100, Italy
| | - G Isella
- L-NESS, Dipartimento di Fisica, Politecnico di Milano, Polo di Como, ViaAnzani 42, Como, 22100, Italy
| | - M de Kruijf
- Department of Physics, University of Basel, Basel, 4056, Switzerland
| | - M J Carballido
- Department of Physics, University of Basel, Basel, 4056, Switzerland
| | - S Svab
- Department of Physics, University of Basel, Basel, 4056, Switzerland
| | - A V Kuhlmann
- Department of Physics, University of Basel, Basel, 4056, Switzerland
| | - S Geyer
- Department of Physics, University of Basel, Basel, 4056, Switzerland
| | - F N M Froning
- Department of Physics, University of Basel, Basel, 4056, Switzerland
| | - H Moon
- Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH, UK
| | - M A Osborne
- Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, UK
| | - D Sejdinovic
- Department of Statistics, University of Oxford, 24-29 St Giles, Oxford, OX1 3LB, UK
| | - G Katsaros
- Institute of Science and Technology Austria, Am Campus 1, Klosterneuburg, 3400, Austria
| | - D M Zumbühl
- Department of Physics, University of Basel, Basel, 4056, Switzerland
| | - G A D Briggs
- Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH, UK
| | - N Ares
- Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, UK.
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3
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Wang CA, John V, Tidjani H, Yu CX, Ivlev AS, Déprez C, van Riggelen-Doelman F, Woods BD, Hendrickx NW, Lawrie WIL, Stehouwer LEA, Oosterhout SD, Sammak A, Friesen M, Scappucci G, de Snoo SL, Rimbach-Russ M, Borsoi F, Veldhorst M. Operating semiconductor quantum processors with hopping spins. Science 2024; 385:447-452. [PMID: 39052794 DOI: 10.1126/science.ado5915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Accepted: 06/14/2024] [Indexed: 07/27/2024]
Abstract
Qubits that can be efficiently controlled are essential for the development of scalable quantum hardware. Although resonant control is used to execute high-fidelity quantum gates, the scalability is challenged by the integration of high-frequency oscillating signals, qubit cross-talk, and heating. Here, we show that by engineering the hopping of spins between quantum dots with a site-dependent spin quantization axis, quantum control can be established with discrete signals. We demonstrate hopping-based quantum logic and obtain single-qubit gate fidelities of 99.97%, coherent shuttling fidelities of 99.992% per hop, and a two-qubit gate fidelity of 99.3%, corresponding to error rates that have been predicted to allow for quantum error correction. We also show that hopping spins constitute a tuning method by statistically mapping the coherence of a 10-quantum dot system. Our results show that dense quantum dot arrays with sparse occupation could be developed for efficient and high-connectivity qubit registers.
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Affiliation(s)
- Chien-An Wang
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
| | - Valentin John
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
| | - Hanifa Tidjani
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
| | - Cécile X Yu
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
| | - Alexander S Ivlev
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
| | - Corentin Déprez
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
| | | | - Benjamin D Woods
- Department of Physics, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Nico W Hendrickx
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
| | - William I L Lawrie
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
| | - Lucas E A Stehouwer
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
| | - Stefan D Oosterhout
- QuTech and Netherlands Organisation for Applied Scientific Research (TNO), 2628 CK Delft, Netherlands
| | - Amir Sammak
- QuTech and Netherlands Organisation for Applied Scientific Research (TNO), 2628 CK Delft, Netherlands
| | - Mark Friesen
- Department of Physics, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Giordano Scappucci
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
| | - Sander L de Snoo
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
| | - Maximilian Rimbach-Russ
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
| | - Francesco Borsoi
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
| | - Menno Veldhorst
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
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4
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Adelsberger C, Bosco S, Klinovaja J, Loss D. Valley-Free Silicon Fins Caused by Shear Strain. PHYSICAL REVIEW LETTERS 2024; 133:037001. [PMID: 39094129 DOI: 10.1103/physrevlett.133.037001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 04/04/2024] [Accepted: 06/05/2024] [Indexed: 08/04/2024]
Abstract
Electron spins confined in silicon quantum dots are promising candidates for large-scale quantum computers. However, the degeneracy of the conduction band of bulk silicon introduces additional levels dangerously close to the window of computational energies, where the quantum information can leak. The energy of the valley states-typically 0.1 meV-depends on hardly controllable atomistic disorder and still constitutes a fundamental limit to the scalability of these architectures. In this work, we introduce designs of complementary metal-oxide-semiconductor (CMOS)-compatible silicon fin field-effect transistors that enhance the energy gap to noncomputational states by more than one order of magnitude. Our devices comprise realistic silicon-germanium nanostructures with a large shear strain, where troublesome valley degrees of freedom are completely removed. The energy of noncomputational states is therefore not affected by unavoidable atomistic disorder and can further be tuned in situ by applied electric fields. Our design ideas are directly applicable to a variety of setups and will offer a blueprint toward silicon-based large-scale quantum processors.
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5
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van Riggelen-Doelman F, Wang CA, de Snoo SL, Lawrie WIL, Hendrickx NW, Rimbach-Russ M, Sammak A, Scappucci G, Déprez C, Veldhorst M. Coherent spin qubit shuttling through germanium quantum dots. Nat Commun 2024; 15:5716. [PMID: 38977681 PMCID: PMC11231167 DOI: 10.1038/s41467-024-49358-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 05/30/2024] [Indexed: 07/10/2024] Open
Abstract
Quantum links can interconnect qubit registers and are therefore essential in networked quantum computing. Semiconductor quantum dot qubits have seen significant progress in the high-fidelity operation of small qubit registers but establishing a compelling quantum link remains a challenge. Here, we show that a spin qubit can be shuttled through multiple quantum dots while preserving its quantum information. Remarkably, we achieve these results using hole spin qubits in germanium, despite the presence of strong spin-orbit interaction. In a minimal quantum dot chain, we accomplish the shuttling of spin basis states over effective lengths beyond 300 microns and demonstrate the coherent shuttling of superposition states over effective lengths corresponding to 9 microns, which we can extend to 49 microns by incorporating dynamical decoupling. These findings indicate qubit shuttling as an effective approach to route qubits within registers and to establish quantum links between registers.
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Affiliation(s)
- Floor van Riggelen-Doelman
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA, Delft, The Netherlands
| | - Chien-An Wang
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA, Delft, The Netherlands
| | - Sander L de Snoo
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA, Delft, The Netherlands
| | - William I L Lawrie
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA, Delft, The Netherlands
| | - Nico W Hendrickx
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA, Delft, The Netherlands
| | - Maximilian Rimbach-Russ
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA, Delft, The Netherlands
| | - Amir Sammak
- QuTech and Netherlands Organisation for Applied Scientific Research (TNO), 2628 CK, Delft, The Netherlands
| | - Giordano Scappucci
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA, Delft, The Netherlands
| | - Corentin Déprez
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA, Delft, The Netherlands.
| | - Menno Veldhorst
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA, Delft, The Netherlands.
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6
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Yi K, Hai YJ, Luo K, Chu J, Zhang L, Zhou Y, Song Y, Liu S, Yan T, Deng XH, Chen Y, Yu D. Robust Quantum Gates against Correlated Noise in Integrated Quantum Chips. PHYSICAL REVIEW LETTERS 2024; 132:250604. [PMID: 38996251 DOI: 10.1103/physrevlett.132.250604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Accepted: 05/22/2024] [Indexed: 07/14/2024]
Abstract
As quantum circuits become more integrated and complex, additional error sources that were previously insignificant start to emerge. Consequently, the fidelity of quantum gates benchmarked under pristine conditions falls short of predicting their performance in realistic circuits. To overcome this problem, we must improve their robustness against pertinent error models besides isolated fidelity. Here, we report the experimental realization of robust quantum gates in superconducting quantum circuits based on a geometric framework for diagnosing and correcting various gate errors. Using quantum process tomography and randomized benchmarking, we demonstrate robust single-qubit gates against quasistatic noise and spatially correlated noise in a broad range of strengths, which are common sources of coherent errors in large-scale quantum circuits. We also apply our method to nonstatic noises and to realize robust two-qubit gates. Our Letter provides a versatile toolbox for achieving noise-resilient complex quantum circuits.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Yuanzhen Chen
- Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
- Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- Guangdong Provincial Key Laboratory of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Dapeng Yu
- Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
- Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- International Quantum Academy (SIQA), Shenzhen 518048, China
- Guangdong Provincial Key Laboratory of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen, 518055, China
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7
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Wyss RM, Kewes G, Marabotti P, Koepfli SM, Schlichting KP, Parzefall M, Bonvin E, Sarott MF, Trassin M, Oezkent M, Lu CH, Gradwohl KP, Perrault T, Habibova L, Marcelli G, Giraldo M, Vermant J, Novotny L, Frimmer M, Weber MC, Heeg S. Bulk-suppressed and surface-sensitive Raman scattering by transferable plasmonic membranes with irregular slot-shaped nanopores. Nat Commun 2024; 15:5236. [PMID: 38897990 PMCID: PMC11187206 DOI: 10.1038/s41467-024-49130-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 05/23/2024] [Indexed: 06/21/2024] Open
Abstract
Raman spectroscopy enables the non-destructive characterization of chemical composition, crystallinity, defects, or strain in countless materials. However, the Raman response of surfaces or thin films is often weak and obscured by dominant bulk signals. Here we overcome this limitation by placing a transferable porous gold membrane, (PAuM) on the surface of interest. Slot-shaped nanopores in the membrane act as plasmonic antennas and enhance the Raman response of the surface or thin film underneath. Simultaneously, the PAuM suppresses the penetration of the excitation laser into the bulk, efficiently blocking its Raman signal. Using graphene as a model surface, we show that this method increases the surface-to-bulk Raman signal ratio by three orders of magnitude. We find that 90% of the Raman enhancement occurs within the top 2.5 nm of the material, demonstrating truly surface-sensitive Raman scattering. To validate our approach, we quantify the strain in a 12.5 nm thin Silicon film and analyze the surface of a LaNiO3 thin film. We observe a Raman mode splitting for the LaNiO3 surface-layer, which is spectroscopic evidence that the surface structure differs from the bulk. These results validate that PAuM gives direct access to Raman signatures of thin films and surfaces.
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Affiliation(s)
- Roman M Wyss
- Institut für Physik und IRIS Adlershof, Humboldt-Universität zu Berlin, 12489, Berlin, Germany
- Soft Materials, Department of Materials, ETH Zürich, 8093 Zürich, Switzerland
| | - Günter Kewes
- Institut für Physik und IRIS Adlershof, Humboldt-Universität zu Berlin, 12489, Berlin, Germany
| | - Pietro Marabotti
- Institut für Physik und IRIS Adlershof, Humboldt-Universität zu Berlin, 12489, Berlin, Germany
| | - Stefan M Koepfli
- Institute of Electromagnetic Fields (IEF), ETH Zürich, 8092 Zürich, Switzerland
| | - Karl-Philipp Schlichting
- Laboratory of Thermodynamics in Emerging Technologies Department of Mechanical and Process Engineering, ETH Zürich, 8092 Zürich, Switzerland
| | | | - Eric Bonvin
- Photonics Lab, ETH Zürich, 8093 Zürich, Switzerland
| | - Martin F Sarott
- Department of Materials, ETH Zürich, 8093 Zürich, Switzerland
| | - Morgan Trassin
- Department of Materials, ETH Zürich, 8093 Zürich, Switzerland
| | | | - Chen-Hsun Lu
- Leibniz-Institut für Kristallzüchtung, 12489, Berlin, Germany
| | | | - Thomas Perrault
- Institut des Molécules et Matériaux du Mans, UMR 6283 CNRS, Le Mans Université, 72085, Le Mans, France
| | - Lala Habibova
- Institut für Physik und IRIS Adlershof, Humboldt-Universität zu Berlin, 12489, Berlin, Germany
| | - Giorgia Marcelli
- Institut für Physik und IRIS Adlershof, Humboldt-Universität zu Berlin, 12489, Berlin, Germany
| | - Marcela Giraldo
- Department of Materials, ETH Zürich, 8093 Zürich, Switzerland
| | - Jan Vermant
- Soft Materials, Department of Materials, ETH Zürich, 8093 Zürich, Switzerland
| | | | | | - Mads C Weber
- Institut des Molécules et Matériaux du Mans, UMR 6283 CNRS, Le Mans Université, 72085, Le Mans, France
| | - Sebastian Heeg
- Institut für Physik und IRIS Adlershof, Humboldt-Universität zu Berlin, 12489, Berlin, Germany.
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8
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Künne M, Willmes A, Oberländer M, Gorjaew C, Teske JD, Bhardwaj H, Beer M, Kammerloher E, Otten R, Seidler I, Xue R, Schreiber LR, Bluhm H. The SpinBus architecture for scaling spin qubits with electron shuttling. Nat Commun 2024; 15:4977. [PMID: 38862531 PMCID: PMC11166970 DOI: 10.1038/s41467-024-49182-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 05/24/2024] [Indexed: 06/13/2024] Open
Abstract
Quantum processor architectures must enable scaling to large qubit numbers while providing two-dimensional qubit connectivity and exquisite operation fidelities. For microwave-controlled semiconductor spin qubits, dense arrays have made considerable progress, but are still limited in size by wiring fan-out and exhibit significant crosstalk between qubits. To overcome these limitations, we introduce the SpinBus architecture, which uses electron shuttling to connect qubits and features low operating frequencies and enhanced qubit coherence. Device simulations for all relevant operations in the Si/SiGe platform validate the feasibility with established semiconductor patterning technology and operation fidelities exceeding 99.9%. Control using room temperature instruments can plausibly support at least 144 qubits, but much larger numbers are conceivable with cryogenic control circuits. Building on the theoretical feasibility of high-fidelity spin-coherent electron shuttling as key enabling factor, the SpinBus architecture may be the basis for a spin-based quantum processor that meets the scalability requirements for practical quantum computing.
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Affiliation(s)
- Matthias Künne
- JARA-FIT Institute for Quantum Information, Forschungszentrum Jülich GmbH and RWTH Aachen University, 52074, Aachen, Germany
| | - Alexander Willmes
- JARA-FIT Institute for Quantum Information, Forschungszentrum Jülich GmbH and RWTH Aachen University, 52074, Aachen, Germany
| | - Max Oberländer
- JARA-FIT Institute for Quantum Information, Forschungszentrum Jülich GmbH and RWTH Aachen University, 52074, Aachen, Germany
| | - Christian Gorjaew
- JARA-FIT Institute for Quantum Information, Forschungszentrum Jülich GmbH and RWTH Aachen University, 52074, Aachen, Germany
| | - Julian D Teske
- JARA-FIT Institute for Quantum Information, Forschungszentrum Jülich GmbH and RWTH Aachen University, 52074, Aachen, Germany
| | - Harsh Bhardwaj
- JARA-FIT Institute for Quantum Information, Forschungszentrum Jülich GmbH and RWTH Aachen University, 52074, Aachen, Germany
| | - Max Beer
- JARA-FIT Institute for Quantum Information, Forschungszentrum Jülich GmbH and RWTH Aachen University, 52074, Aachen, Germany
| | - Eugen Kammerloher
- JARA-FIT Institute for Quantum Information, Forschungszentrum Jülich GmbH and RWTH Aachen University, 52074, Aachen, Germany
| | - René Otten
- JARA-FIT Institute for Quantum Information, Forschungszentrum Jülich GmbH and RWTH Aachen University, 52074, Aachen, Germany
- ARQUE Systems GmbH, 52074, Aachen, Germany
| | - Inga Seidler
- JARA-FIT Institute for Quantum Information, Forschungszentrum Jülich GmbH and RWTH Aachen University, 52074, Aachen, Germany
| | - Ran Xue
- JARA-FIT Institute for Quantum Information, Forschungszentrum Jülich GmbH and RWTH Aachen University, 52074, Aachen, Germany
| | - Lars R Schreiber
- JARA-FIT Institute for Quantum Information, Forschungszentrum Jülich GmbH and RWTH Aachen University, 52074, Aachen, Germany.
- ARQUE Systems GmbH, 52074, Aachen, Germany.
| | - Hendrik Bluhm
- JARA-FIT Institute for Quantum Information, Forschungszentrum Jülich GmbH and RWTH Aachen University, 52074, Aachen, Germany.
- ARQUE Systems GmbH, 52074, Aachen, Germany.
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9
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Xiang L, Chen J, Zhu Z, Song Z, Bao Z, Zhu X, Jin F, Wang K, Xu S, Zou Y, Li H, Wang Z, Song C, Yue A, Partridge J, Guo Q, Mondaini R, Wang H, Scalettar RT. Enhanced quantum state transfer by circumventing quantum chaotic behavior. Nat Commun 2024; 15:4918. [PMID: 38858357 PMCID: PMC11164980 DOI: 10.1038/s41467-024-48791-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 05/10/2024] [Indexed: 06/12/2024] Open
Abstract
The ability to realize high-fidelity quantum communication is one of the many facets required to build generic quantum computing devices. In addition to quantum processing, sensing, and storage, transferring the resulting quantum states demands a careful design that finds no parallel in classical communication. Existing experimental demonstrations of quantum information transfer in solid-state quantum systems are largely confined to small chains with few qubits, often relying upon non-generic schemes. Here, by using a superconducting quantum circuit featuring thirty-six tunable qubits, accompanied by general optimization procedures deeply rooted in overcoming quantum chaotic behavior, we demonstrate a scalable protocol for transferring few-particle quantum states in a two-dimensional quantum network. These include single-qubit excitation, two-qubit entangled states, and two excitations for which many-body effects are present. Our approach, combined with the quantum circuit's versatility, paves the way to short-distance quantum communication for connecting distributed quantum processors or registers, even if hampered by inherent imperfections in actual quantum devices.
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Affiliation(s)
- Liang Xiang
- Zhejiang Key Laboratory of Micro-nano Quantum Chips and Quantum Control, School of Physics, Zhejiang University, Hangzhou, 310027, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 311215, China
| | - Jiachen Chen
- Zhejiang Key Laboratory of Micro-nano Quantum Chips and Quantum Control, School of Physics, Zhejiang University, Hangzhou, 310027, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 311215, China
| | - Zitian Zhu
- Zhejiang Key Laboratory of Micro-nano Quantum Chips and Quantum Control, School of Physics, Zhejiang University, Hangzhou, 310027, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 311215, China
| | - Zixuan Song
- Zhejiang Key Laboratory of Micro-nano Quantum Chips and Quantum Control, School of Physics, Zhejiang University, Hangzhou, 310027, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 311215, China
| | - Zehang Bao
- Zhejiang Key Laboratory of Micro-nano Quantum Chips and Quantum Control, School of Physics, Zhejiang University, Hangzhou, 310027, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 311215, China
| | - Xuhao Zhu
- Zhejiang Key Laboratory of Micro-nano Quantum Chips and Quantum Control, School of Physics, Zhejiang University, Hangzhou, 310027, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 311215, China
| | - Feitong Jin
- Zhejiang Key Laboratory of Micro-nano Quantum Chips and Quantum Control, School of Physics, Zhejiang University, Hangzhou, 310027, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 311215, China
| | - Ke Wang
- Zhejiang Key Laboratory of Micro-nano Quantum Chips and Quantum Control, School of Physics, Zhejiang University, Hangzhou, 310027, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 311215, China
| | - Shibo Xu
- Zhejiang Key Laboratory of Micro-nano Quantum Chips and Quantum Control, School of Physics, Zhejiang University, Hangzhou, 310027, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 311215, China
| | - Yiren Zou
- Zhejiang Key Laboratory of Micro-nano Quantum Chips and Quantum Control, School of Physics, Zhejiang University, Hangzhou, 310027, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 311215, China
| | - Hekang Li
- Zhejiang Key Laboratory of Micro-nano Quantum Chips and Quantum Control, School of Physics, Zhejiang University, Hangzhou, 310027, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 311215, China
| | - Zhen Wang
- Zhejiang Key Laboratory of Micro-nano Quantum Chips and Quantum Control, School of Physics, Zhejiang University, Hangzhou, 310027, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 311215, China
| | - Chao Song
- Zhejiang Key Laboratory of Micro-nano Quantum Chips and Quantum Control, School of Physics, Zhejiang University, Hangzhou, 310027, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 311215, China
| | - Alexander Yue
- Department of Physics and Astronomy, University of California, Davis, CA, 95616, USA
| | - Justine Partridge
- Department of Physics and Astronomy, University of California, Davis, CA, 95616, USA
| | - Qiujiang Guo
- Zhejiang Key Laboratory of Micro-nano Quantum Chips and Quantum Control, School of Physics, Zhejiang University, Hangzhou, 310027, China.
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 311215, China.
| | - Rubem Mondaini
- Beijing Computational Science Research Center, Beijing, 100193, China.
- Department of Physics, University of Houston, Houston, TX, 77004, USA.
- Texas Center for Superconductivity, University of Houston, Houston, TX, 77204, USA.
| | - H Wang
- Zhejiang Key Laboratory of Micro-nano Quantum Chips and Quantum Control, School of Physics, Zhejiang University, Hangzhou, 310027, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 311215, China
| | - Richard T Scalettar
- Department of Physics and Astronomy, University of California, Davis, CA, 95616, USA.
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10
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Ruckriegel MJ, Gächter LM, Kealhofer D, Bahrami Panah M, Tong C, Adam C, Masseroni M, Duprez H, Garreis R, Watanabe K, Taniguchi T, Wallraff A, Ihn T, Ensslin K, Huang WW. Electric Dipole Coupling of a Bilayer Graphene Quantum Dot to a High-Impedance Microwave Resonator. NANO LETTERS 2024; 24:7508-7514. [PMID: 38833415 PMCID: PMC11194813 DOI: 10.1021/acs.nanolett.4c01791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 05/31/2024] [Accepted: 05/31/2024] [Indexed: 06/06/2024]
Abstract
We implement circuit quantum electrodynamics (cQED) with quantum dots in bilayer graphene, a maturing material platform that can host long-lived spin and valley states. Our device combines a high-impedance (Zr ≈ 1 kΩ) superconducting microwave resonator with a double quantum dot electrostatically defined in a graphene-based van der Waals heterostructure. Electric dipole coupling between the subsystems allows the resonator to sense the electric susceptibility of the double quantum dot from which we reconstruct its charge stability diagram. We achieve sensitive and fast detection of the interdot transition with a signal-to-noise ratio of 3.5 within 1 μs integration time. The charge-photon interaction is quantified in the dispersive and resonant regimes by comparing the resonator response to input-output theory, yielding a coupling strength of g/2π = 49.7 MHz. Our results introduce cQED as a probe for quantum dots in van der Waals materials and indicate a path toward coherent charge-photon coupling with bilayer graphene quantum dots.
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Affiliation(s)
- Max J. Ruckriegel
- Laboratory
for Solid State Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Lisa M. Gächter
- Laboratory
for Solid State Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - David Kealhofer
- Laboratory
for Solid State Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Mohsen Bahrami Panah
- Laboratory
for Solid State Physics, ETH Zürich, CH-8093 Zürich, Switzerland
- Quantum
Center, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Chuyao Tong
- Laboratory
for Solid State Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Christoph Adam
- Laboratory
for Solid State Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Michele Masseroni
- Laboratory
for Solid State Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Hadrien Duprez
- Laboratory
for Solid State Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Rebekka Garreis
- Laboratory
for Solid State Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Kenji Watanabe
- Research
Center for Electronic and Optical Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Takashi Taniguchi
- Research
Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Andreas Wallraff
- Laboratory
for Solid State Physics, ETH Zürich, CH-8093 Zürich, Switzerland
- Quantum
Center, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Thomas Ihn
- Laboratory
for Solid State Physics, ETH Zürich, CH-8093 Zürich, Switzerland
- Quantum
Center, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Klaus Ensslin
- Laboratory
for Solid State Physics, ETH Zürich, CH-8093 Zürich, Switzerland
- Quantum
Center, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Wei Wister Huang
- Laboratory
for Solid State Physics, ETH Zürich, CH-8093 Zürich, Switzerland
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11
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Li L, Santis LD, Harris IBW, Chen KC, Gao Y, Christen I, Choi H, Trusheim M, Song Y, Errando-Herranz C, Du J, Hu Y, Clark G, Ibrahim MI, Gilbert G, Han R, Englund D. Heterogeneous integration of spin-photon interfaces with a CMOS platform. Nature 2024; 630:70-76. [PMID: 38811730 DOI: 10.1038/s41586-024-07371-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 04/02/2024] [Indexed: 05/31/2024]
Abstract
Colour centres in diamond have emerged as a leading solid-state platform for advancing quantum technologies, satisfying the DiVincenzo criteria1 and recently achieving quantum advantage in secret key distribution2. Blueprint studies3-5 indicate that general-purpose quantum computing using local quantum communication networks will require millions of physical qubits to encode thousands of logical qubits, presenting an open scalability challenge. Here we introduce a modular quantum system-on-chip (QSoC) architecture that integrates thousands of individually addressable tin-vacancy spin qubits in two-dimensional arrays of quantum microchiplets into an application-specific integrated circuit designed for cryogenic control. We demonstrate crucial fabrication steps and architectural subcomponents, including QSoC transfer by means of a 'lock-and-release' method for large-scale heterogeneous integration, high-throughput spin-qubit calibration and spectral tuning, and efficient spin state preparation and measurement. This QSoC architecture supports full connectivity for quantum memory arrays by spectral tuning across spin-photon frequency channels. Design studies building on these measurements indicate further scaling potential by means of increased qubit density, larger QSoC active regions and optical networking across QSoC modules.
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Affiliation(s)
- Linsen Li
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA.
| | - Lorenzo De Santis
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
- QuTech, Delft University of Technology, Delft, Netherlands
| | - Isaac B W Harris
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Kevin C Chen
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Yihuai Gao
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Ian Christen
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Hyeongrak Choi
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Matthew Trusheim
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
- DEVCOM, Army Research Laboratory, Adelphi, MD, USA
| | - Yixuan Song
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Carlos Errando-Herranz
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Institute of Physics, University of Münster, Münster, Germany
| | - Jiahui Du
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Yong Hu
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Genevieve Clark
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
- The MITRE Corporation, Bedford, MA, USA
| | - Mohamed I Ibrahim
- School of Electrical and Computer Engineering, Cornell University, Ithaca, NY, USA
| | | | - Ruonan Han
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Dirk Englund
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA.
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12
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Neyens S, Zietz OK, Watson TF, Luthi F, Nethwewala A, George HC, Henry E, Islam M, Wagner AJ, Borjans F, Connors EJ, Corrigan J, Curry MJ, Keith D, Kotlyar R, Lampert LF, Mądzik MT, Millard K, Mohiyaddin FA, Pellerano S, Pillarisetty R, Ramsey M, Savytskyy R, Schaal S, Zheng G, Ziegler J, Bishop NC, Bojarski S, Roberts J, Clarke JS. Probing single electrons across 300-mm spin qubit wafers. Nature 2024; 629:80-85. [PMID: 38693414 PMCID: PMC11062914 DOI: 10.1038/s41586-024-07275-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 03/05/2024] [Indexed: 05/03/2024]
Abstract
Building a fault-tolerant quantum computer will require vast numbers of physical qubits. For qubit technologies based on solid-state electronic devices1-3, integrating millions of qubits in a single processor will require device fabrication to reach a scale comparable to that of the modern complementary metal-oxide-semiconductor (CMOS) industry. Equally important, the scale of cryogenic device testing must keep pace to enable efficient device screening and to improve statistical metrics such as qubit yield and voltage variation. Spin qubits1,4,5 based on electrons in Si have shown impressive control fidelities6-9 but have historically been challenged by yield and process variation10-12. Here we present a testing process using a cryogenic 300-mm wafer prober13 to collect high-volume data on the performance of hundreds of industry-manufactured spin qubit devices at 1.6 K. This testing method provides fast feedback to enable optimization of the CMOS-compatible fabrication process, leading to high yield and low process variation. Using this system, we automate measurements of the operating point of spin qubits and investigate the transitions of single electrons across full wafers. We analyse the random variation in single-electron operating voltages and find that the optimized fabrication process leads to low levels of disorder at the 300-mm scale. Together, these results demonstrate the advances that can be achieved through the application of CMOS-industry techniques to the fabrication and measurement of spin qubit devices.
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13
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Wang Y, Wang T, Zhu XY. Virtual Photon-Mediated Quantum State Transfer and Remote Entanglement between Spin Qubits in Quantum Dots Using Superadiabatic Pulses. ENTROPY (BASEL, SWITZERLAND) 2024; 26:379. [PMID: 38785628 PMCID: PMC11119106 DOI: 10.3390/e26050379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 04/21/2024] [Accepted: 04/27/2024] [Indexed: 05/25/2024]
Abstract
Spin qubits in semiconductor quantum dots are an attractive candidate for scalable quantum information processing. Reliable quantum state transfer and entanglement between spatially separated spin qubits is a highly desirable but challenging goal. Here, we propose a fast and high-fidelity quantum state transfer scheme for two spin qubits mediated by virtual microwave photons. Our general strategy involves using a superadiabatic pulse to eliminate non-adiabatic transitions, without the need for increased control complexity. We show that arbitrary quantum state transfer can be achieved with a fidelity of 95.1% within a 60 ns short time under realistic parameter conditions. We also demonstrate the robustness of this scheme to experimental imperfections and environmental noises. Furthermore, this scheme can be directly applied to the generation of a remote Bell entangled state with a fidelity as high as 97.6%. These results pave the way for fault-tolerant quantum computation on spin quantum network architecture platforms.
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Affiliation(s)
- Yue Wang
- School of Mechanical and Electronic Engineering, Suzhou University, Suzhou 234000, China
| | - Ting Wang
- School of Mechanical and Electronic Engineering, Suzhou University, Suzhou 234000, China
| | - Xing-Yu Zhu
- School of Mechanical and Electronic Engineering, Suzhou University, Suzhou 234000, China
- Institute of Quantum Information Technology, Suzhou University, Suzhou 234000, China
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14
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Xue R, Beer M, Seidler I, Humpohl S, Tu JS, Trellenkamp S, Struck T, Bluhm H, Schreiber LR. Si/SiGe QuBus for single electron information-processing devices with memory and micron-scale connectivity function. Nat Commun 2024; 15:2296. [PMID: 38485971 PMCID: PMC10940717 DOI: 10.1038/s41467-024-46519-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 02/26/2024] [Indexed: 03/18/2024] Open
Abstract
The connectivity within single carrier information-processing devices requires transport and storage of single charge quanta. Single electrons have been adiabatically transported while confined to a moving quantum dot in short, all-electrical Si/SiGe shuttle device, called quantum bus (QuBus). Here we show a QuBus spanning a length of 10 μm and operated by only six simply-tunable voltage pulses. We introduce a characterization method, called shuttle-tomography, to benchmark the potential imperfections and local shuttle-fidelity of the QuBus. The fidelity of the single-electron shuttle across the full device and back (a total distance of 19 μm) is (99.7 ± 0.3) %. Using the QuBus, we position and detect up to 34 electrons and initialize a register of 34 quantum dots with arbitrarily chosen patterns of zero and single-electrons. The simple operation signals, compatibility with industry fabrication and low spin-environment-interaction in 28Si/SiGe, promises long-range spin-conserving transport of spin qubits for quantum connectivity in quantum computing architectures.
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Affiliation(s)
- Ran Xue
- JARA-FIT Institute for Quantum Information, Forschungszentrum Jülich GmbH and RWTH Aachen University, Aachen, Germany
| | - Max Beer
- JARA-FIT Institute for Quantum Information, Forschungszentrum Jülich GmbH and RWTH Aachen University, Aachen, Germany
| | - Inga Seidler
- JARA-FIT Institute for Quantum Information, Forschungszentrum Jülich GmbH and RWTH Aachen University, Aachen, Germany
| | - Simon Humpohl
- JARA-FIT Institute for Quantum Information, Forschungszentrum Jülich GmbH and RWTH Aachen University, Aachen, Germany
- ARQUE Systems GmbH, Aachen, Germany
| | - Jhih-Sian Tu
- Helmholtz Nano Facility (HNF), Forschungszentrum Jülich, Jülich, Germany
| | - Stefan Trellenkamp
- Helmholtz Nano Facility (HNF), Forschungszentrum Jülich, Jülich, Germany
| | - Tom Struck
- JARA-FIT Institute for Quantum Information, Forschungszentrum Jülich GmbH and RWTH Aachen University, Aachen, Germany
- ARQUE Systems GmbH, Aachen, Germany
| | - Hendrik Bluhm
- JARA-FIT Institute for Quantum Information, Forschungszentrum Jülich GmbH and RWTH Aachen University, Aachen, Germany
- ARQUE Systems GmbH, Aachen, Germany
| | - Lars R Schreiber
- JARA-FIT Institute for Quantum Information, Forschungszentrum Jülich GmbH and RWTH Aachen University, Aachen, Germany.
- ARQUE Systems GmbH, Aachen, Germany.
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15
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Huang JY, Su RY, Lim WH, Feng M, van Straaten B, Severin B, Gilbert W, Dumoulin Stuyck N, Tanttu T, Serrano S, Cifuentes JD, Hansen I, Seedhouse AE, Vahapoglu E, Leon RCC, Abrosimov NV, Pohl HJ, Thewalt MLW, Hudson FE, Escott CC, Ares N, Bartlett SD, Morello A, Saraiva A, Laucht A, Dzurak AS, Yang CH. High-fidelity spin qubit operation and algorithmic initialization above 1 K. Nature 2024; 627:772-777. [PMID: 38538941 PMCID: PMC10972758 DOI: 10.1038/s41586-024-07160-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Accepted: 02/05/2024] [Indexed: 04/01/2024]
Abstract
The encoding of qubits in semiconductor spin carriers has been recognized as a promising approach to a commercial quantum computer that can be lithographically produced and integrated at scale1-10. However, the operation of the large number of qubits required for advantageous quantum applications11-13 will produce a thermal load exceeding the available cooling power of cryostats at millikelvin temperatures. As the scale-up accelerates, it becomes imperative to establish fault-tolerant operation above 1 K, at which the cooling power is orders of magnitude higher14-18. Here we tune up and operate spin qubits in silicon above 1 K, with fidelities in the range required for fault-tolerant operations at these temperatures19-21. We design an algorithmic initialization protocol to prepare a pure two-qubit state even when the thermal energy is substantially above the qubit energies and incorporate radiofrequency readout to achieve fidelities up to 99.34% for both readout and initialization. We also demonstrate single-qubit Clifford gate fidelities up to 99.85% and a two-qubit gate fidelity of 98.92%. These advances overcome the fundamental limitation that the thermal energy must be well below the qubit energies for the high-fidelity operation to be possible, surmounting a main obstacle in the pathway to scalable and fault-tolerant quantum computation.
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Affiliation(s)
- Jonathan Y Huang
- School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales, Australia.
| | - Rocky Y Su
- School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales, Australia
| | - Wee Han Lim
- School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales, Australia
- Diraq, Sydney, New South Wales, Australia
| | - MengKe Feng
- School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales, Australia
| | | | - Brandon Severin
- School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales, Australia
- Department of Engineering Science, University of Oxford, Oxford, UK
| | - Will Gilbert
- School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales, Australia
- Diraq, Sydney, New South Wales, Australia
| | - Nard Dumoulin Stuyck
- School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales, Australia
- Diraq, Sydney, New South Wales, Australia
| | - Tuomo Tanttu
- School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales, Australia
- Diraq, Sydney, New South Wales, Australia
| | - Santiago Serrano
- School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales, Australia
| | - Jesus D Cifuentes
- School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales, Australia
| | - Ingvild Hansen
- School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales, Australia
| | - Amanda E Seedhouse
- School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales, Australia
| | - Ensar Vahapoglu
- School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales, Australia
- Diraq, Sydney, New South Wales, Australia
| | - Ross C C Leon
- School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales, Australia
- Quantum Motion Technologies, London, UK
| | | | | | - Michael L W Thewalt
- Department of Physics, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Fay E Hudson
- School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales, Australia
- Diraq, Sydney, New South Wales, Australia
| | - Christopher C Escott
- School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales, Australia
- Diraq, Sydney, New South Wales, Australia
| | - Natalia Ares
- Department of Engineering Science, University of Oxford, Oxford, UK
| | - Stephen D Bartlett
- Centre for Engineered Quantum Systems, School of Physics, University of Sydney, Sydney, New South Wales, Australia
| | - Andrea Morello
- School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales, Australia
| | - Andre Saraiva
- School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales, Australia
- Diraq, Sydney, New South Wales, Australia
| | - Arne Laucht
- School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales, Australia
- Diraq, Sydney, New South Wales, Australia
| | - Andrew S Dzurak
- School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales, Australia.
- Diraq, Sydney, New South Wales, Australia.
| | - Chih Hwan Yang
- School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales, Australia.
- Diraq, Sydney, New South Wales, Australia.
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16
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Fernández de Fuentes I, Botzem T, Johnson MAI, Vaartjes A, Asaad S, Mourik V, Hudson FE, Itoh KM, Johnson BC, Jakob AM, McCallum JC, Jamieson DN, Dzurak AS, Morello A. Navigating the 16-dimensional Hilbert space of a high-spin donor qudit with electric and magnetic fields. Nat Commun 2024; 15:1380. [PMID: 38355747 PMCID: PMC11258329 DOI: 10.1038/s41467-024-45368-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 01/19/2024] [Indexed: 02/16/2024] Open
Abstract
Efficient scaling and flexible control are key aspects of useful quantum computing hardware. Spins in semiconductors combine quantum information processing with electrons, holes or nuclei, control with electric or magnetic fields, and scalable coupling via exchange or dipole interaction. However, accessing large Hilbert space dimensions has remained challenging, due to the short-distance nature of the interactions. Here, we present an atom-based semiconductor platform where a 16-dimensional Hilbert space is built by the combined electron-nuclear states of a single antimony donor in silicon. We demonstrate the ability to navigate this large Hilbert space using both electric and magnetic fields, with gate fidelity exceeding 99.8% on the nuclear spin, and unveil fine details of the system Hamiltonian and its susceptibility to control and noise fields. These results establish high-spin donors as a rich platform for practical quantum information and to explore quantum foundations.
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Affiliation(s)
| | - Tim Botzem
- School of Electrical Engineering and Telecommunication, UNSW Sydney, Sydney, NSW, Australia
| | - Mark A I Johnson
- School of Electrical Engineering and Telecommunication, UNSW Sydney, Sydney, NSW, Australia
| | - Arjen Vaartjes
- School of Electrical Engineering and Telecommunication, UNSW Sydney, Sydney, NSW, Australia
| | - Serwan Asaad
- School of Electrical Engineering and Telecommunication, UNSW Sydney, Sydney, NSW, Australia
| | - Vincent Mourik
- School of Electrical Engineering and Telecommunication, UNSW Sydney, Sydney, NSW, Australia
| | - Fay E Hudson
- School of Electrical Engineering and Telecommunication, UNSW Sydney, Sydney, NSW, Australia
- Diraq, Sydney, NSW, Australia
| | - Kohei M Itoh
- School of Fundamental Science and Technology, Keio University, Yokohama, Japan
| | - Brett C Johnson
- School of Science, RMIT University, Melbourne, VIC, Australia
| | - Alexander M Jakob
- School of Physics, University of Melbourne, Melbourne, VIC, Australia
| | | | - David N Jamieson
- School of Physics, University of Melbourne, Melbourne, VIC, Australia
| | - Andrew S Dzurak
- School of Electrical Engineering and Telecommunication, UNSW Sydney, Sydney, NSW, Australia
- Diraq, Sydney, NSW, Australia
| | - Andrea Morello
- School of Electrical Engineering and Telecommunication, UNSW Sydney, Sydney, NSW, Australia.
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17
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Struck T, Volmer M, Visser L, Offermann T, Xue R, Tu JS, Trellenkamp S, Cywiński Ł, Bluhm H, Schreiber LR. Spin-EPR-pair separation by conveyor-mode single electron shuttling in Si/SiGe. Nat Commun 2024; 15:1325. [PMID: 38351007 PMCID: PMC10864332 DOI: 10.1038/s41467-024-45583-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 01/29/2024] [Indexed: 02/16/2024] Open
Abstract
Long-ranged coherent qubit coupling is a missing function block for scaling up spin qubit based quantum computing solutions. Spin-coherent conveyor-mode electron-shuttling could enable spin quantum-chips with scalable and sparse qubit-architecture. Its key feature is the operation by only few easily tuneable input terminals and compatibility with industrial gate-fabrication. Single electron shuttling in conveyor-mode in a 420 nm long quantum bus has been demonstrated previously. Here we investigate the spin coherence during conveyor-mode shuttling by separation and rejoining an Einstein-Podolsky-Rosen (EPR) spin-pair. Compared to previous work we boost the shuttle velocity by a factor of 10000. We observe a rising spin-qubit dephasing time with the longer shuttle distances due to motional narrowing and estimate the spin-shuttle infidelity due to dephasing to be 0.7% for a total shuttle distance of nominal 560 nm. Shuttling several loops up to an accumulated distance of 3.36 μm, spin-entanglement of the EPR pair is still detectable, giving good perspective for our approach of a shuttle-based scalable quantum computing architecture in silicon.
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Affiliation(s)
- Tom Struck
- JARA-FIT Institute for Quantum Information, Forschungszentrum Jülich GmbH and RWTH Aachen University, Aachen, Germany
- ARQUE Systems GmbH, Aachen, Germany
| | - Mats Volmer
- JARA-FIT Institute for Quantum Information, Forschungszentrum Jülich GmbH and RWTH Aachen University, Aachen, Germany
| | - Lino Visser
- JARA-FIT Institute for Quantum Information, Forschungszentrum Jülich GmbH and RWTH Aachen University, Aachen, Germany
| | - Tobias Offermann
- JARA-FIT Institute for Quantum Information, Forschungszentrum Jülich GmbH and RWTH Aachen University, Aachen, Germany
| | - Ran Xue
- JARA-FIT Institute for Quantum Information, Forschungszentrum Jülich GmbH and RWTH Aachen University, Aachen, Germany
| | - Jhih-Sian Tu
- Helmholtz Nano Facility (HNF), Forschungszentrum Jülich, Jülich, Germany
| | - Stefan Trellenkamp
- Helmholtz Nano Facility (HNF), Forschungszentrum Jülich, Jülich, Germany
| | - Łukasz Cywiński
- Institute of Physics, Polish Academy of Sciences, Warsaw, Poland
| | - Hendrik Bluhm
- JARA-FIT Institute for Quantum Information, Forschungszentrum Jülich GmbH and RWTH Aachen University, Aachen, Germany
- ARQUE Systems GmbH, Aachen, Germany
| | - Lars R Schreiber
- JARA-FIT Institute for Quantum Information, Forschungszentrum Jülich GmbH and RWTH Aachen University, Aachen, Germany.
- ARQUE Systems GmbH, Aachen, Germany.
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18
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Liu XF, Matsumoto Y, Fujita T, Ludwig A, Wieck AD, Oiwa A. Accelerated Adiabatic Passage of a Single Electron Spin Qubit in Quantum Dots. PHYSICAL REVIEW LETTERS 2024; 132:027002. [PMID: 38277587 DOI: 10.1103/physrevlett.132.027002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 10/11/2023] [Accepted: 12/16/2023] [Indexed: 01/28/2024]
Abstract
Adiabatic processes can keep the quantum system in its instantaneous eigenstate, which is robust to noises and dissipation. However, it is limited by sufficiently slow evolution. Here, we experimentally demonstrate the transitionless quantum driving (TLQD) of the shortcuts to adiabaticity in gate-defined semiconductor quantum dots (QDs) to greatly accelerate the conventional adiabatic passage for the first time. For a given efficiency of quantum state transfer, the acceleration can be more than twofold. The dynamic properties also prove that the TLQD can guarantee fast and high-fidelity quantum state transfer. In order to compensate for the diabatic errors caused by dephasing noises, the modified TLQD is proposed and demonstrated in experiment by enlarging the width of the counterdiabatic drivings. The benchmarking shows that the state transfer fidelity of 97.8% can be achieved. This work will greatly promote researches and applications about quantum simulations and adiabatic quantum computation based on the gate-defined QDs.
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Affiliation(s)
- Xiao-Fei Liu
- SANKEN, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
| | - Yuta Matsumoto
- SANKEN, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - Takafumi Fujita
- SANKEN, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - Arne Ludwig
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstraße 150, Gebäude NB, D-44780 Bochum, Germany
| | - Andreas D Wieck
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstraße 150, Gebäude NB, D-44780 Bochum, Germany
| | - Akira Oiwa
- SANKEN, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
- Center for Quantum Information and Quantum Biology (QIQB), Osaka University, Osaka 565-0871, Japan
- Center for Spintronics Research Network (CSRN), Graduate School of Engineering Science, Osaka University, Osaka 560-8531, Japan
- Spintronics Research Network Division, OTRI, Osaka University, Osaka 565-0871, Japan
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19
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Nakamura S, Matsumaru D, Yamahata G, Oe T, Chae DH, Okazaki Y, Takada S, Maruyama M, Fujiwara A, Kaneko NH. Universality and Multiplication of Gigahertz-Operated Silicon Pumps with Parts Per Million-Level Uncertainty. NANO LETTERS 2024; 24:9-15. [PMID: 38115185 DOI: 10.1021/acs.nanolett.3c02858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
The universality of physical phenomena is a pivotal concept underlying quantum standards. In this context, the realization of a quantum current standard using silicon single-electron pumps necessitates the verification of the equivalence across multiple devices. Herein, we experimentally investigate the universality of pumped currents from two different silicon single-electron devices which are placed inside the cryogen-free dilution refrigerator whose temperature (mixing chamber plate) was ∼150 mK under the operation of the pump devices. By direct comparison using an ultrastable current amplifier as a galvanometer, we confirm that two pumped currents are consistent with ∼1 ppm uncertainty. Furthermore, we realize quantum-current multiplication with a similar uncertainty by adding the currents of two different gigahertz (GHz)-operated silicon pumps, whose generated currents are confirmed to be identical. These results pave the way for realizing a quantum current standard in the nanoampere range and a quantum metrology triangle experiment using silicon pump devices.
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Affiliation(s)
- Shuji Nakamura
- National Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8563, Japan
| | - Daiki Matsumaru
- National Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8563, Japan
| | - Gento Yamahata
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi, Kanagawa 243-0198, Japan
| | - Takehiko Oe
- National Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8563, Japan
| | - Dong-Hun Chae
- Korea Research Institute of Standards and Science (KRISS), Daejeon 34113, Republic of Korea
| | - Yuma Okazaki
- National Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8563, Japan
| | - Shintaro Takada
- National Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8563, Japan
| | - Michitaka Maruyama
- National Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8563, Japan
| | - Akira Fujiwara
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi, Kanagawa 243-0198, Japan
| | - Nobu-Hisa Kaneko
- National Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8563, Japan
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20
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Wang Q, Liu J, Lyu D, Wang J. Ultrahigh-fidelity spatial mode quantum gates in high-dimensional space by diffractive deep neural networks. LIGHT, SCIENCE & APPLICATIONS 2024; 13:10. [PMID: 38177149 PMCID: PMC10767004 DOI: 10.1038/s41377-023-01336-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Revised: 10/30/2023] [Accepted: 11/12/2023] [Indexed: 01/06/2024]
Abstract
While the spatial mode of photons is widely used in quantum cryptography, its potential for quantum computation remains largely unexplored. Here, we showcase the use of the multi-dimensional spatial mode of photons to construct a series of high-dimensional quantum gates, achieved through the use of diffractive deep neural networks (D2NNs). Notably, our gates demonstrate high fidelity of up to 99.6(2)%, as characterized by quantum process tomography. Our experimental implementation of these gates involves a programmable array of phase layers in a compact and scalable device, capable of performing complex operations or even quantum circuits. We also demonstrate the efficacy of the D2NN gates by successfully implementing the Deutsch algorithm and propose an intelligent deployment protocol that involves self-configuration and self-optimization. Moreover, we conduct a comparative analysis of the D2NN gate's performance to the wave-front matching approach. Overall, our work opens a door for designing specific quantum gates using deep learning, with the potential for reliable execution of quantum computation.
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Affiliation(s)
- Qianke Wang
- Wuhan National Laboratory for Optoelectronics and School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, 430074, Hubei, China
- Optics Valley Laboratory, Wuhan, 430074, Hubei, China
| | - Jun Liu
- Wuhan National Laboratory for Optoelectronics and School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, 430074, Hubei, China
- Optics Valley Laboratory, Wuhan, 430074, Hubei, China
| | - Dawei Lyu
- Wuhan National Laboratory for Optoelectronics and School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, 430074, Hubei, China
- Optics Valley Laboratory, Wuhan, 430074, Hubei, China
| | - Jian Wang
- Wuhan National Laboratory for Optoelectronics and School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, 430074, Hubei, China.
- Optics Valley Laboratory, Wuhan, 430074, Hubei, China.
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21
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Borsoi F, Hendrickx NW, John V, Meyer M, Motz S, van Riggelen F, Sammak A, de Snoo SL, Scappucci G, Veldhorst M. Shared control of a 16 semiconductor quantum dot crossbar array. NATURE NANOTECHNOLOGY 2024; 19:21-27. [PMID: 37640909 PMCID: PMC10796274 DOI: 10.1038/s41565-023-01491-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2022] [Accepted: 07/20/2023] [Indexed: 08/31/2023]
Abstract
The efficient control of a large number of qubits is one of the most challenging aspects for practical quantum computing. Current approaches in solid-state quantum technology are based on brute-force methods, where each and every qubit requires at least one unique control line-an approach that will become unsustainable when scaling to the required millions of qubits. Here, inspired by random-access architectures in classical electronics, we introduce the shared control of semiconductor quantum dots to efficiently operate a two-dimensional crossbar array in planar germanium. We tune the entire array, comprising 16 quantum dots, to the few-hole regime. We then confine an odd number of holes in each site to isolate an unpaired spin per dot. Moving forward, we demonstrate on a vertical and a horizontal double quantum dot a method for the selective control of the interdot coupling and achieve a tunnel coupling tunability over more than 10 GHz. The operation of a quantum electronic device with fewer control terminals than tunable experimental parameters represents a compelling step forward in the construction of scalable quantum technology.
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Affiliation(s)
- Francesco Borsoi
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands.
| | - Nico W Hendrickx
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Valentin John
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Marcel Meyer
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Sayr Motz
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Floor van Riggelen
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Amir Sammak
- QuTech and Netherlands Organisation for Applied Scientific Research (TNO), Delft, The Netherlands
| | - Sander L de Snoo
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Giordano Scappucci
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Menno Veldhorst
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands.
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22
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Meyer M, Déprez C, Meijer IN, Unseld FK, Karwal S, Sammak A, Scappucci G, Vandersypen LMK, Veldhorst M. Single-Electron Occupation in Quantum Dot Arrays at Selectable Plunger Gate Voltage. NANO LETTERS 2023; 23:11593-11600. [PMID: 38091376 PMCID: PMC10755753 DOI: 10.1021/acs.nanolett.3c03349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Revised: 12/06/2023] [Accepted: 12/07/2023] [Indexed: 12/28/2023]
Abstract
The small footprint of semiconductor qubits is favorable for scalable quantum computing. However, their size also makes them sensitive to their local environment and variations in the gate structure. Currently, each device requires tailored gate voltages to confine a single charge per quantum dot, clearly challenging scalability. Here, we tune these gate voltages and equalize them solely through the temporary application of stress voltages. In a double quantum dot, we reach a stable (1,1) charge state at identical and predetermined plunger gate voltage and for various interdot couplings. Applying our findings, we tune a 2 × 2 quadruple quantum dot such that the (1,1,1,1) charge state is reached when all plunger gates are set to 1 V. The ability to define required gate voltages may relax requirements on control electronics and operations for spin qubit devices, providing means to advance quantum hardware.
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Affiliation(s)
- Marcel Meyer
- QuTech
and Kavli Institute of Nanoscience, Delft
University of Technology, PO Box 5046, 2600 GA Delft, The
Netherlands
| | - Corentin Déprez
- QuTech
and Kavli Institute of Nanoscience, Delft
University of Technology, PO Box 5046, 2600 GA Delft, The
Netherlands
| | - Ilja N. Meijer
- QuTech
and Kavli Institute of Nanoscience, Delft
University of Technology, PO Box 5046, 2600 GA Delft, The
Netherlands
| | - Florian K. Unseld
- QuTech
and Kavli Institute of Nanoscience, Delft
University of Technology, PO Box 5046, 2600 GA Delft, The
Netherlands
| | - Saurabh Karwal
- QuTech
and Netherlands Organisation for Applied Scientific Research (TNO), PO Box 155, 2600 AD Delft, The Netherlands
| | - Amir Sammak
- QuTech
and Netherlands Organisation for Applied Scientific Research (TNO), PO Box 155, 2600 AD Delft, The Netherlands
| | - Giordano Scappucci
- QuTech
and Kavli Institute of Nanoscience, Delft
University of Technology, PO Box 5046, 2600 GA Delft, The
Netherlands
| | - Lieven M. K. Vandersypen
- QuTech
and Kavli Institute of Nanoscience, Delft
University of Technology, PO Box 5046, 2600 GA Delft, The
Netherlands
| | - Menno Veldhorst
- QuTech
and Kavli Institute of Nanoscience, Delft
University of Technology, PO Box 5046, 2600 GA Delft, The
Netherlands
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23
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Abideen ZU, Choi JG, Yuwono JA, Lee WJ, Murugappan K, Kumar PV, Nisbet DR, Trần-Phú T, Yoon MH, Tricoli A. Structural Engineering Three-Dimensional Nano-Heterojunction Networks for High-Performance Photochemical Sensing. ACS APPLIED MATERIALS & INTERFACES 2023; 15:56464-56477. [PMID: 37987616 DOI: 10.1021/acsami.3c12668] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Nanoscale heterojunction networks are increasingly regarded as promising functional materials for a variety of optoelectronic and photocatalytic devices. Despite their superior charge-carrier separation efficiency, a major challenge remains in the optimization of their surface properties, with surface defects playing a major role in charge trapping and recombination. Here, we report the effective engineering of the photocatalytic properties of nanoscale heterojunction networks via deep ultraviolet photoactivation throughout their cross-section. For the first time, in-depth XPS analysis of very thick (∼10 μm) NixOy-ZnO films reveals localized p-n nanoheterojunctions with tunable oxygen vacancies (Vo) originating from both NixOy and ZnO nanocrystals. Optimizing the amount of oxygen vacancies leads to a 30-fold increase in the photochemoresistive response of these networks, enabling the detection of representative analyte concentrations down to 2 and 20 ppb at an optimal temperature of 150 °C and room temperature, respectively. Density functional theory calculations reveal that this performance enhancement is presumably due to an 80% increase in the analyte adsorption energy. This flexible nanofabrication approach in conjunction with straightforward vacancy control via photoactivation provides an effective strategy for engineering the photocatalytic activity of porous metal oxide semiconductor networks with applications in chemical sensors, photodetectors, and photoelectrochemical cells.
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Affiliation(s)
- Zain Ul Abideen
- Nanotechnology Research Laboratory, Research School of Chemistry, College of Science, Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Jun-Gyu Choi
- School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea
| | - Jodie A Yuwono
- School of Chemical Engineering, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Won-June Lee
- School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea
| | - Krishnan Murugappan
- Nanotechnology Research Laboratory, Research School of Chemistry, College of Science, Australian National University, Canberra, Australian Capital Territory 2601, Australia
- CSIRO, Mineral Resources, Private Bag 10, Clayton South, Victoria 3169, Australia
| | - Priyank Vijaya Kumar
- School of Chemical Engineering, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - David R Nisbet
- The Graeme Clark Institute, The University of Melbourne, Melbourne, Victoria 3010, Australia
- Department of Biomedical Engineering, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Thành Trần-Phú
- Nanotechnology Research Laboratory, Research School of Chemistry, College of Science, Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Myung-Han Yoon
- School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea
| | - Antonio Tricoli
- Nanotechnology Research Laboratory, Research School of Chemistry, College of Science, Australian National University, Canberra, Australian Capital Territory 2601, Australia
- Nanotechnology Research Laboratory, Faculty of Engineering, University of Sydney, Sydney, New South Wales 2006, Australia
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24
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Bosco S, Geyer S, Camenzind LC, Eggli RS, Fuhrer A, Warburton RJ, Zumbühl DM, Egues JC, Kuhlmann AV, Loss D. Phase-Driving Hole Spin Qubits. PHYSICAL REVIEW LETTERS 2023; 131:197001. [PMID: 38000439 DOI: 10.1103/physrevlett.131.197001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Accepted: 10/03/2023] [Indexed: 11/26/2023]
Abstract
The spin-orbit interaction in spin qubits enables spin-flip transitions, resulting in Rabi oscillations when an external microwave field is resonant with the qubit frequency. Here, we introduce an alternative driving mechanism mediated by the strong spin-orbit interactions in hole spin qubits, where a far-detuned oscillating field couples to the qubit phase. Phase-driving at radio frequencies, orders of magnitude slower than the microwave qubit frequency, induces highly nontrivial spin dynamics, violating the Rabi resonance condition. By using a qubit integrated in a silicon fin field-effect transistor, we demonstrate a controllable suppression of resonant Rabi oscillations and their revivals at tunable sidebands. These sidebands enable alternative qubit control schemes using global fields and local far-detuned pulses, facilitating the design of dense large-scale qubit architectures with local qubit addressability. Phase-driving also decouples Rabi oscillations from noise, an effect due to a gapped Floquet spectrum and can enable Floquet engineering high-fidelity gates in future quantum processors.
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Affiliation(s)
- Stefano Bosco
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| | - Simon Geyer
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| | - Leon C Camenzind
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| | - Rafael S Eggli
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| | - Andreas Fuhrer
- IBM Research Europe-Zurich, Säumerstrasse 4, CH-8803 Rüschlikon, Switzerland
| | - Richard J Warburton
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| | - Dominik M Zumbühl
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| | - J Carlos Egues
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
- Instituto de Física de São Carlos, Universidade de São Paulo, 13560-970 São Carlos, São Paulo, Brazil
| | - Andreas V Kuhlmann
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| | - Daniel Loss
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
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25
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Chen S, Cotler J, Huang HY, Li J. The complexity of NISQ. Nat Commun 2023; 14:6001. [PMID: 37752125 PMCID: PMC10522708 DOI: 10.1038/s41467-023-41217-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Accepted: 08/25/2023] [Indexed: 09/28/2023] Open
Abstract
The recent proliferation of NISQ devices has made it imperative to understand their power. In this work, we define and study the complexity class NISQ, which encapsulates problems that can be efficiently solved by a classical computer with access to noisy quantum circuits. We establish super-polynomial separations in the complexity among classical computation, NISQ, and fault-tolerant quantum computation to solve some problems based on modifications of Simon's problems. We then consider the power of NISQ for three well-studied problems. For unstructured search, we prove that NISQ cannot achieve a Grover-like quadratic speedup over classical computers. For the Bernstein-Vazirani problem, we show that NISQ only needs a number of queries logarithmic in what is required for classical computers. Finally, for a quantum state learning problem, we prove that NISQ is exponentially weaker than classical computers with access to noiseless constant-depth quantum circuits.
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Affiliation(s)
- Sitan Chen
- Department of Electrical Engineering and Computer Science, University of California, Berkeley, Berkeley, CA, USA.
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, USA.
| | - Jordan Cotler
- Society of Fellows, Harvard University, Cambridge, MA, USA.
| | - Hsin-Yuan Huang
- Institute for Quantum Information and Matter, CAltech, Pasadena, CA, USA.
- Department of Computing and Mathematical Sciences, CAltech, Pasadena, CA, USA.
| | - Jerry Li
- Microsoft Research AI, Redmond, WA, USA.
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26
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Zhang Y, Xu S, Liu J, Jin W, Lefkidis G, Hübner W, Li C. Optically Driven Both Classical and Quantum Unary, Binary, and Ternary Logic Gates on Co-Decorated Graphene Nanoflakes. J Phys Chem Lett 2023; 14:8107-8113. [PMID: 37657090 DOI: 10.1021/acs.jpclett.3c01917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/03/2023]
Abstract
Nanospintronics holds great potential for providing high-speed, low-power, and high-density logic and memory elements in future computational devices. Here, using ab initio many-body theory, we suggest a nanoscale framework for building quantum computation elements, based on individual magnetic atoms deposited on graphene nanoflakes. We show the great possibilities of this proposal by exemplarily presenting four quantum gates, namely, the unary Pauli-X, Pauli-Y, Pauli-Z, and Hadamard gates, as well as the universal classical ternary Toffoli gate, which preserves information entropy and is therefore fully reversible and minimally energy consuming. All our gates operate within the subpicosecond time scale and reach fidelities well above 90%. We demonstrate the ability to control the spin direction and localization, as well as to create superposition states and to control the quantum phase of states, which are indispensable ingredients of quantum computers. Additionally, being optically driven, their predicted operating speed by far beats that of modern quantum computers.
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Affiliation(s)
- Yiming Zhang
- School of Science, Xi'an University of Architecture and Technology, Xi'an 710055, China
- School of Mechanics, Civil Engineering and Architecture, Northwestern Polytechnical University, Xi'an 710072, China
| | - Shuai Xu
- School of Mechanics, Civil Engineering and Architecture, Northwestern Polytechnical University, Xi'an 710072, China
- Research and Development Institute of Northwestern Polytechnical University in Shenzhen, Shenzhen 518057, China
| | - Jing Liu
- Institute of Theoretical Chemistry, Ulm University, 89081 Ulm, Germany
| | - Wei Jin
- School of Physics and Information Technology, Shaanxi Normal University, Xi'an 710119, China
| | - Georgios Lefkidis
- School of Mechanics, Civil Engineering and Architecture, Northwestern Polytechnical University, Xi'an 710072, China
- Department of Physics, RPTU Kaiserslautern-Landau, P.O. Box 3049, Kaiserslautern 67663, Germany
| | - Wolfgang Hübner
- Department of Physics, RPTU Kaiserslautern-Landau, P.O. Box 3049, Kaiserslautern 67663, Germany
| | - Chun Li
- School of Mechanics, Civil Engineering and Architecture, Northwestern Polytechnical University, Xi'an 710072, China
- Research and Development Institute of Northwestern Polytechnical University in Shenzhen, Shenzhen 518057, China
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27
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He L, Liu D, Gao J, Zhang W, Zhang H, Feng X, Huang Y, Cui K, Liu F, Zhang W, Zhang X. Super-compact universal quantum logic gates with inverse-designed elements. SCIENCE ADVANCES 2023; 9:eadg6685. [PMID: 37235652 DOI: 10.1126/sciadv.adg6685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 04/20/2023] [Indexed: 05/28/2023]
Abstract
Integrated quantum photonic circuit is a promising platform for the realization of quantum information processing in the future. To achieve the large-scale quantum photonic circuits, the applied quantum logic gates should be as small as possible for the high-density integration on chips. Here, we report the implementation of super-compact universal quantum logic gates on silicon chips by the method of inverse design. In particular, the fabricated controlled-NOT gate and Hadamard gate are both nearly a vacuum wavelength, being the smallest optical quantum gates reported up to now. We further design the quantum circuit by cascading these fundamental gates to perform arbitrary quantum processing, where the corresponding size is about several orders smaller than that of previous quantum photonic circuits. Our study paves the way for the realization of large-scale quantum photonic chips with integrated sources and can have important applications in the field of quantum information processes.
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Affiliation(s)
- Lu He
- Key Laboratory of advanced optoelectronic quantum architecture and measurements of Ministry of Education, Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems, School of Physics, Beijing Institute of Technology, 100081 Beijing, China
| | - Dongning Liu
- Frontier Science Center for Quantum Information, Beijing National Research Center for Information Science and Technology (BNRist), Electronic Engineering Department, Tsinghua University, Beijing 100084, China
| | - Jingxing Gao
- Frontier Science Center for Quantum Information, Beijing National Research Center for Information Science and Technology (BNRist), Electronic Engineering Department, Tsinghua University, Beijing 100084, China
| | - Weixuan Zhang
- Key Laboratory of advanced optoelectronic quantum architecture and measurements of Ministry of Education, Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems, School of Physics, Beijing Institute of Technology, 100081 Beijing, China
| | - Huizhen Zhang
- Key Laboratory of advanced optoelectronic quantum architecture and measurements of Ministry of Education, Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems, School of Physics, Beijing Institute of Technology, 100081 Beijing, China
| | - Xue Feng
- Frontier Science Center for Quantum Information, Beijing National Research Center for Information Science and Technology (BNRist), Electronic Engineering Department, Tsinghua University, Beijing 100084, China
| | - Yidong Huang
- Frontier Science Center for Quantum Information, Beijing National Research Center for Information Science and Technology (BNRist), Electronic Engineering Department, Tsinghua University, Beijing 100084, China
- Beijing Academy of Quantum Information Sciences, 100193 Beijing, China
| | - Kaiyu Cui
- Frontier Science Center for Quantum Information, Beijing National Research Center for Information Science and Technology (BNRist), Electronic Engineering Department, Tsinghua University, Beijing 100084, China
| | - Fang Liu
- Frontier Science Center for Quantum Information, Beijing National Research Center for Information Science and Technology (BNRist), Electronic Engineering Department, Tsinghua University, Beijing 100084, China
| | - Wei Zhang
- Frontier Science Center for Quantum Information, Beijing National Research Center for Information Science and Technology (BNRist), Electronic Engineering Department, Tsinghua University, Beijing 100084, China
- Beijing Academy of Quantum Information Sciences, 100193 Beijing, China
| | - Xiangdong Zhang
- Key Laboratory of advanced optoelectronic quantum architecture and measurements of Ministry of Education, Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems, School of Physics, Beijing Institute of Technology, 100081 Beijing, China
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28
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Lin T, Gu SS, Xu YQ, Jiang SL, Ye SK, Wang BC, Li HO, Guo GC, Zou CL, Hu X, Cao G, Guo GP. Collective Microwave Response for Multiple Gate-Defined Double Quantum Dots. NANO LETTERS 2023; 23:4176-4182. [PMID: 37133858 DOI: 10.1021/acs.nanolett.3c00036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
We fabricate and characterize a hybrid quantum device that consists of five gate-defined double quantum dots (DQDs) and a high-impedance NbTiN transmission resonator. The controllable interactions between DQDs and the resonator are spectroscopically explored by measuring the microwave transmission through the resonator in the detuning parameter space. Utilizing the high tunability of the system parameters and the high cooperativity (Ctotal > 17.6) interaction between the qubit ensemble and the resonator, we tune the charge-photon coupling and observe the collective microwave response changing from linear to nonlinear. Our results present the maximum number of DQDs coupled to a resonator and manifest a potential platform for scaling up qubits and studying collective quantum effects in semiconductor-superconductor hybrid cavity quantum electrodynamics systems.
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Affiliation(s)
- Ting Lin
- Chinese Academy of Science Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- Chinese Academy of Science Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Si-Si Gu
- Chinese Academy of Science Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- Chinese Academy of Science Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Yong-Qiang Xu
- Chinese Academy of Science Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- Chinese Academy of Science Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Shun-Li Jiang
- Chinese Academy of Science Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- Chinese Academy of Science Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Shu-Kun Ye
- Chinese Academy of Science Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- Chinese Academy of Science Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Bao-Chuan Wang
- Chinese Academy of Science Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- Chinese Academy of Science Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Hai-Ou Li
- Chinese Academy of Science Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- Chinese Academy of Science Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
| | - Guang-Can Guo
- Chinese Academy of Science Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- Chinese Academy of Science Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
| | - Chang-Ling Zou
- Chinese Academy of Science Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- Chinese Academy of Science Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
| | - Xuedong Hu
- Department of Physics, University at Buffalo, State University of New York, Buffalo, New York 14260-1500, United States of America
| | - Gang Cao
- Chinese Academy of Science Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- Chinese Academy of Science Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
| | - Guo-Ping Guo
- Chinese Academy of Science Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- Chinese Academy of Science Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
- Origin Quantum Computing Company Limited, Hefei, Anhui 230088, China
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29
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Wang Z, Feng M, Serrano S, Gilbert W, Leon RCC, Tanttu T, Mai P, Liang D, Huang JY, Su Y, Lim WH, Hudson FE, Escott CC, Morello A, Yang CH, Dzurak AS, Saraiva A, Laucht A. Jellybean Quantum Dots in Silicon for Qubit Coupling and On-Chip Quantum Chemistry. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2208557. [PMID: 36805699 DOI: 10.1002/adma.202208557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Revised: 01/13/2023] [Indexed: 05/12/2023]
Abstract
The small size and excellent integrability of silicon metal-oxide-semiconductor (SiMOS) quantum dot spin qubits make them an attractive system for mass-manufacturable, scaled-up quantum processors. Furthermore, classical control electronics can be integrated on-chip, in-between the qubits, if an architecture with sparse arrays of qubits is chosen. In such an architecture qubits are either transported across the chip via shuttling or coupled via mediating quantum systems over short-to-intermediate distances. This paper investigates the charge and spin characteristics of an elongated quantum dot-a so-called jellybean quantum dot-for the prospects of acting as a qubit-qubit coupler. Charge transport, charge sensing, and magneto-spectroscopy measurements are performed on a SiMOS quantum dot device at mK temperature and compared to Hartree-Fock multi-electron simulations. At low electron occupancies where disorder effects and strong electron-electron interaction dominate over the electrostatic confinement potential, the data reveals the formation of three coupled dots, akin to a tunable, artificial molecule. One dot is formed centrally under the gate and two are formed at the edges. At high electron occupancies, these dots merge into one large dot with well-defined spin states, verifying that jellybean dots have the potential to be used as qubit couplers in future quantum computing architectures.
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Affiliation(s)
- Zeheng Wang
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - MengKe Feng
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Santiago Serrano
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - William Gilbert
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
- Diraq, Sydney, NSW, 2052, Australia
| | - Ross C C Leon
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Tuomo Tanttu
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
- Diraq, Sydney, NSW, 2052, Australia
| | - Philip Mai
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Dylan Liang
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Jonathan Y Huang
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Yue Su
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Wee Han Lim
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
- Diraq, Sydney, NSW, 2052, Australia
| | - Fay E Hudson
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
- Diraq, Sydney, NSW, 2052, Australia
| | - Christopher C Escott
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
- Diraq, Sydney, NSW, 2052, Australia
| | - Andrea Morello
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Chih Hwan Yang
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
- Diraq, Sydney, NSW, 2052, Australia
| | - Andrew S Dzurak
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
- Diraq, Sydney, NSW, 2052, Australia
| | - Andre Saraiva
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
- Diraq, Sydney, NSW, 2052, Australia
| | - Arne Laucht
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
- Diraq, Sydney, NSW, 2052, Australia
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30
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Meyer M, Déprez C, van Abswoude TR, Meijer IN, Liu D, Wang CA, Karwal S, Oosterhout S, Borsoi F, Sammak A, Hendrickx NW, Scappucci G, Veldhorst M. Electrical Control of Uniformity in Quantum Dot Devices. NANO LETTERS 2023; 23:2522-2529. [PMID: 36975126 PMCID: PMC10103318 DOI: 10.1021/acs.nanolett.2c04446] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 03/20/2023] [Indexed: 06/18/2023]
Abstract
Highly uniform quantum systems are essential for the practical implementation of scalable quantum processors. While quantum dot spin qubits based on semiconductor technology are a promising platform for large-scale quantum computing, their small size makes them particularly sensitive to their local environment. Here, we present a method to electrically obtain a high degree of uniformity in the intrinsic potential landscape using hysteretic shifts of the gate voltage characteristics. We demonstrate the tuning of pinch-off voltages in quantum dot devices over hundreds of millivolts that then remain stable at least for hours. Applying our method, we homogenize the pinch-off voltages of the plunger gates in a linear array for four quantum dots, reducing the spread in pinch-off voltages by one order of magnitude. This work provides a new tool for the tuning of quantum dot devices and offers new perspectives for the implementation of scalable spin qubit arrays.
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Affiliation(s)
- Marcel Meyer
- QuTech
and Kavli Institute of Nanoscience, Delft
University of Technology, PO Box 5046, 2600 GA Delft, The Netherlands
| | - Corentin Déprez
- QuTech
and Kavli Institute of Nanoscience, Delft
University of Technology, PO Box 5046, 2600 GA Delft, The Netherlands
| | - Timo R. van Abswoude
- QuTech
and Kavli Institute of Nanoscience, Delft
University of Technology, PO Box 5046, 2600 GA Delft, The Netherlands
| | - Ilja N. Meijer
- QuTech
and Kavli Institute of Nanoscience, Delft
University of Technology, PO Box 5046, 2600 GA Delft, The Netherlands
| | - Dingshan Liu
- QuTech
and Kavli Institute of Nanoscience, Delft
University of Technology, PO Box 5046, 2600 GA Delft, The Netherlands
| | - Chien-An Wang
- QuTech
and Kavli Institute of Nanoscience, Delft
University of Technology, PO Box 5046, 2600 GA Delft, The Netherlands
| | - Saurabh Karwal
- QuTech
and Netherlands Organisation for Applied Scientific Research (TNO), PO Box 155, 2600 AD Delft, The Netherlands
| | - Stefan Oosterhout
- QuTech
and Netherlands Organisation for Applied Scientific Research (TNO), PO Box 155, 2600 AD Delft, The Netherlands
| | - Francesco Borsoi
- QuTech
and Kavli Institute of Nanoscience, Delft
University of Technology, PO Box 5046, 2600 GA Delft, The Netherlands
| | - Amir Sammak
- QuTech
and Netherlands Organisation for Applied Scientific Research (TNO), PO Box 155, 2600 AD Delft, The Netherlands
| | - Nico W. Hendrickx
- QuTech
and Kavli Institute of Nanoscience, Delft
University of Technology, PO Box 5046, 2600 GA Delft, The Netherlands
| | - Giordano Scappucci
- QuTech
and Kavli Institute of Nanoscience, Delft
University of Technology, PO Box 5046, 2600 GA Delft, The Netherlands
| | - Menno Veldhorst
- QuTech
and Kavli Institute of Nanoscience, Delft
University of Technology, PO Box 5046, 2600 GA Delft, The Netherlands
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31
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Sivak VV, Eickbusch A, Royer B, Singh S, Tsioutsios I, Ganjam S, Miano A, Brock BL, Ding AZ, Frunzio L, Girvin SM, Schoelkopf RJ, Devoret MH. Real-time quantum error correction beyond break-even. Nature 2023; 616:50-55. [PMID: 36949196 DOI: 10.1038/s41586-023-05782-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 02/02/2023] [Indexed: 03/24/2023]
Abstract
The ambition of harnessing the quantum for computation is at odds with the fundamental phenomenon of decoherence. The purpose of quantum error correction (QEC) is to counteract the natural tendency of a complex system to decohere. This cooperative process, which requires participation of multiple quantum and classical components, creates a special type of dissipation that removes the entropy caused by the errors faster than the rate at which these errors corrupt the stored quantum information. Previous experimental attempts to engineer such a process1-7 faced the generation of an excessive number of errors that overwhelmed the error-correcting capability of the process itself. Whether it is practically possible to utilize QEC for extending quantum coherence thus remains an open question. Here we answer it by demonstrating a fully stabilized and error-corrected logical qubit whose quantum coherence is substantially longer than that of all the imperfect quantum components involved in the QEC process, beating the best of them with a coherence gain of G = 2.27 ± 0.07. We achieve this performance by combining innovations in several domains including the fabrication of superconducting quantum circuits and model-free reinforcement learning.
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Affiliation(s)
- V V Sivak
- Department of Physics, Yale University, New Haven, CT, USA.
- Department of Applied Physics, Yale University, New Haven, CT, USA.
- Yale Quantum Institute, Yale University, New Haven, CT, USA.
- Google AI Quantum, Santa Barbara, CA, USA.
| | - A Eickbusch
- Department of Physics, Yale University, New Haven, CT, USA
- Department of Applied Physics, Yale University, New Haven, CT, USA
- Yale Quantum Institute, Yale University, New Haven, CT, USA
| | - B Royer
- Department of Physics, Yale University, New Haven, CT, USA
- Department of Applied Physics, Yale University, New Haven, CT, USA
- Yale Quantum Institute, Yale University, New Haven, CT, USA
- Institut Quantique, Université de Sherbrooke, Sherbrooke, Quebec, Canada
- Département de Physique, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - S Singh
- Department of Physics, Yale University, New Haven, CT, USA
- Department of Applied Physics, Yale University, New Haven, CT, USA
- Yale Quantum Institute, Yale University, New Haven, CT, USA
| | - I Tsioutsios
- Department of Physics, Yale University, New Haven, CT, USA
- Department of Applied Physics, Yale University, New Haven, CT, USA
- Yale Quantum Institute, Yale University, New Haven, CT, USA
| | - S Ganjam
- Department of Physics, Yale University, New Haven, CT, USA
- Department of Applied Physics, Yale University, New Haven, CT, USA
- Yale Quantum Institute, Yale University, New Haven, CT, USA
| | - A Miano
- Department of Physics, Yale University, New Haven, CT, USA
- Department of Applied Physics, Yale University, New Haven, CT, USA
- Yale Quantum Institute, Yale University, New Haven, CT, USA
| | - B L Brock
- Department of Physics, Yale University, New Haven, CT, USA
- Department of Applied Physics, Yale University, New Haven, CT, USA
- Yale Quantum Institute, Yale University, New Haven, CT, USA
| | - A Z Ding
- Department of Physics, Yale University, New Haven, CT, USA
- Department of Applied Physics, Yale University, New Haven, CT, USA
- Yale Quantum Institute, Yale University, New Haven, CT, USA
| | - L Frunzio
- Department of Physics, Yale University, New Haven, CT, USA
- Department of Applied Physics, Yale University, New Haven, CT, USA
- Yale Quantum Institute, Yale University, New Haven, CT, USA
| | - S M Girvin
- Department of Physics, Yale University, New Haven, CT, USA
- Department of Applied Physics, Yale University, New Haven, CT, USA
- Yale Quantum Institute, Yale University, New Haven, CT, USA
| | - R J Schoelkopf
- Department of Physics, Yale University, New Haven, CT, USA
- Department of Applied Physics, Yale University, New Haven, CT, USA
- Yale Quantum Institute, Yale University, New Haven, CT, USA
| | - M H Devoret
- Department of Physics, Yale University, New Haven, CT, USA.
- Department of Applied Physics, Yale University, New Haven, CT, USA.
- Yale Quantum Institute, Yale University, New Haven, CT, USA.
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32
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Reducing charge noise in quantum dots by using thin silicon quantum wells. Nat Commun 2023; 14:1385. [PMID: 36914637 PMCID: PMC10011559 DOI: 10.1038/s41467-023-36951-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 02/25/2023] [Indexed: 03/16/2023] Open
Abstract
Charge noise in the host semiconductor degrades the performance of spin-qubits and poses an obstacle to control large quantum processors. However, it is challenging to engineer the heterogeneous material stack of gate-defined quantum dots to improve charge noise systematically. Here, we address the semiconductor-dielectric interface and the buried quantum well of a 28Si/SiGe heterostructure and show the connection between charge noise, measured locally in quantum dots, and global disorder in the host semiconductor, measured with macroscopic Hall bars. In 5 nm thick 28Si quantum wells, we find that improvements in the scattering properties and uniformity of the two-dimensional electron gas over a 100 mm wafer correspond to a significant reduction in charge noise, with a minimum value of 0.29 ± 0.02 μeV/Hz½ at 1 Hz averaged over several quantum dots. We extrapolate the measured charge noise to simulated dephasing times to CZ-gate fidelities that improve nearly one order of magnitude. These results point to a clean and quiet crystalline environment for integrating long-lived and high-fidelity spin qubits into a larger system.
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33
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Weinstein AJ, Reed MD, Jones AM, Andrews RW, Barnes D, Blumoff JZ, Euliss LE, Eng K, Fong BH, Ha SD, Hulbert DR, Jackson CAC, Jura M, Keating TE, Kerckhoff J, Kiselev AA, Matten J, Sabbir G, Smith A, Wright J, Rakher MT, Ladd TD, Borselli MG. Universal logic with encoded spin qubits in silicon. Nature 2023; 615:817-822. [PMID: 36746190 PMCID: PMC10060158 DOI: 10.1038/s41586-023-05777-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 01/31/2023] [Indexed: 02/08/2023]
Abstract
Quantum computation features known examples of hardware acceleration for certain problems, but is challenging to realize because of its susceptibility to small errors from noise or imperfect control. The principles of fault tolerance may enable computational acceleration with imperfect hardware, but they place strict requirements on the character and correlation of errors1. For many qubit technologies2-21, some challenges to achieving fault tolerance can be traced to correlated errors arising from the need to control qubits by injecting microwave energy matching qubit resonances. Here we demonstrate an alternative approach to quantum computation that uses energy-degenerate encoded qubit states controlled by nearest-neighbour contact interactions that partially swap the spin states of electrons with those of their neighbours. Calibrated sequences of such partial swaps, implemented using only voltage pulses, allow universal quantum control while bypassing microwave-associated correlated error sources1,22-28. We use an array of six 28Si/SiGe quantum dots, built using a platform that is capable of extending in two dimensions following processes used in conventional microelectronics29. We quantify the operational fidelity of universal control of two encoded qubits using interleaved randomized benchmarking30, finding a fidelity of 96.3% ± 0.7% for encoded controlled NOT operations and 99.3% ± 0.5% for encoded SWAP. The quantum coherence offered by enriched silicon5-9,16,18,20,22,27,29,31-37, the all-electrical and low-crosstalk-control of partial swap operations1,22-28 and the configurable insensitivity of our encoding to certain error sources28,33,34,38 all combine to offer a strong pathway towards scalable fault tolerance and computational advantage.
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Affiliation(s)
| | | | | | | | | | | | | | - Kevin Eng
- HRL Laboratories, LLC, Malibu, CA, USA
| | | | - Sieu D Ha
- HRL Laboratories, LLC, Malibu, CA, USA
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34
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Nikolaeva AS, Kiktenko EO, Fedorov AK. Generalized Toffoli Gate Decomposition Using Ququints: Towards Realizing Grover's Algorithm with Qudits. ENTROPY (BASEL, SWITZERLAND) 2023; 25:387. [PMID: 36832752 PMCID: PMC9955871 DOI: 10.3390/e25020387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 02/14/2023] [Accepted: 02/15/2023] [Indexed: 06/18/2023]
Abstract
Qubits, which are the quantum counterparts of classical bits, are used as basic information units for quantum information processing, whereas underlying physical information carriers, e.g., (artificial) atoms or ions, admit encoding of more complex multilevel states-qudits. Recently, significant attention has been paid to the idea of using qudit encoding as a way for further scaling quantum processors. In this work, we present an efficient decomposition of the generalized Toffoli gate on five-level quantum systems-so-called ququints-that use ququints' space as the space of two qubits with a joint ancillary state. The basic two-qubit operation we use is a version of the controlled-phase gate. The proposed N-qubit Toffoli gate decomposition has O(N) asymptotic depth and does not use ancillary qubits. We then apply our results for Grover's algorithm, where we indicate on the sizable advantage of using the qudit-based approach with the proposed decomposition in comparison to the standard qubit case. We expect that our results are applicable for quantum processors based on various physical platforms, such as trapped ions, neutral atoms, protonic systems, superconducting circuits, and others.
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Affiliation(s)
- Anstasiia S. Nikolaeva
- Russian Quantum Center, Skolkovo, Moscow 121205, Russia
- National University of Science and Technology “MISIS”, Moscow 119049, Russia
| | - Evgeniy O. Kiktenko
- Russian Quantum Center, Skolkovo, Moscow 121205, Russia
- National University of Science and Technology “MISIS”, Moscow 119049, Russia
| | - Aleksey K. Fedorov
- Russian Quantum Center, Skolkovo, Moscow 121205, Russia
- National University of Science and Technology “MISIS”, Moscow 119049, Russia
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35
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Kranz L, Gorman SK, Thorgrimsson B, Monir S, He Y, Keith D, Charde K, Keizer JG, Rahman R, Simmons MY. The Use of Exchange Coupled Atom Qubits as Atomic-Scale Magnetic Field Sensors. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2201625. [PMID: 36208088 DOI: 10.1002/adma.202201625] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Revised: 09/09/2022] [Indexed: 06/16/2023]
Abstract
Phosphorus atoms in silicon offer a rich quantum computing platform where both nuclear and electron spins can be used to store and process quantum information. While individual control of electron and nuclear spins has been demonstrated, the interplay between them during qubit operations has been largely unexplored. This study investigates the use of exchange-based operation between donor bound electron spins to probe the local magnetic fields experienced by the qubits with exquisite precision at the atomic scale. To achieve this, coherent exchange oscillations are performed between two electron spin qubits, where the left and right qubits are hosted by three and two phosphorus donors, respectively. The frequency spectrum of exchange oscillations shows quantized changes in the local magnetic fields at the qubit sites, corresponding to the different hyperfine coupling between the electron and each of the qubit-hosting nuclear spins. This ability to sense the hyperfine fields of individual nuclear spins using the exchange interaction constitutes a unique metrology technique, which reveals the exact crystallographic arrangements of the phosphorus atoms in the silicon crystal for each qubit. The detailed knowledge obtained of the local magnetic environment can then be used to engineer hyperfine fields in multi-donor qubits for high-fidelity two-qubit gates.
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Affiliation(s)
- Ludwik Kranz
- Centre of Excellence for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales, 2052, Australia
- Silicon Quantum Computing Pty Ltd., UNSW, Sydney, 2052, Australia
| | - Samuel K Gorman
- Centre of Excellence for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales, 2052, Australia
- Silicon Quantum Computing Pty Ltd., UNSW, Sydney, 2052, Australia
| | - Brandur Thorgrimsson
- Centre of Excellence for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales, 2052, Australia
- Silicon Quantum Computing Pty Ltd., UNSW, Sydney, 2052, Australia
| | - Serajum Monir
- Centre of Excellence for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales, 2052, Australia
- Silicon Quantum Computing Pty Ltd., UNSW, Sydney, 2052, Australia
| | - Yu He
- Centre of Excellence for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales, 2052, Australia
- Silicon Quantum Computing Pty Ltd., UNSW, Sydney, 2052, Australia
| | - Daniel Keith
- Centre of Excellence for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales, 2052, Australia
- Silicon Quantum Computing Pty Ltd., UNSW, Sydney, 2052, Australia
| | - Keshavi Charde
- Centre of Excellence for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales, 2052, Australia
- Silicon Quantum Computing Pty Ltd., UNSW, Sydney, 2052, Australia
| | - Joris G Keizer
- Centre of Excellence for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales, 2052, Australia
- Silicon Quantum Computing Pty Ltd., UNSW, Sydney, 2052, Australia
| | - Rajib Rahman
- Centre of Excellence for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales, 2052, Australia
- Silicon Quantum Computing Pty Ltd., UNSW, Sydney, 2052, Australia
| | - Michelle Y Simmons
- Centre of Excellence for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales, 2052, Australia
- Silicon Quantum Computing Pty Ltd., UNSW, Sydney, 2052, Australia
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36
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Gilbert W, Tanttu T, Lim WH, Feng M, Huang JY, Cifuentes JD, Serrano S, Mai PY, Leon RCC, Escott CC, Itoh KM, Abrosimov NV, Pohl HJ, Thewalt MLW, Hudson FE, Morello A, Laucht A, Yang CH, Saraiva A, Dzurak AS. On-demand electrical control of spin qubits. NATURE NANOTECHNOLOGY 2023; 18:131-136. [PMID: 36635331 DOI: 10.1038/s41565-022-01280-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Accepted: 10/24/2022] [Indexed: 06/17/2023]
Abstract
Once called a 'classically non-describable two-valuedness' by Pauli, the electron spin forms a qubit that is naturally robust to electric fluctuations. Paradoxically, a common control strategy is the integration of micromagnets to enhance the coupling between spins and electric fields, which, in turn, hampers noise immunity and adds architectural complexity. Here we exploit a switchable interaction between spins and orbital motion of electrons in silicon quantum dots, without a micromagnet. The weak effects of relativistic spin-orbit interaction in silicon are enhanced, leading to a speed up in Rabi frequency by a factor of up to 650 by controlling the energy quantization of electrons in the nanostructure. Fast electrical control is demonstrated in multiple devices and electronic configurations. Using the electrical drive, we achieve a coherence time T2,Hahn ≈ 50 μs, fast single-qubit gates with Tπ/2 = 3 ns and gate fidelities of 99.93%, probed by randomized benchmarking. High-performance all-electrical control improves the prospects for scalable silicon quantum computing.
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Affiliation(s)
- Will Gilbert
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia.
- Diraq, Sydney, New South Wales, Australia.
| | - Tuomo Tanttu
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
- Diraq, Sydney, New South Wales, Australia
| | - Wee Han Lim
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
- Diraq, Sydney, New South Wales, Australia
| | - MengKe Feng
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
| | - Jonathan Y Huang
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
| | - Jesus D Cifuentes
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
| | - Santiago Serrano
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
| | - Philip Y Mai
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
| | - Ross C C Leon
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
| | - Christopher C Escott
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
- Diraq, Sydney, New South Wales, Australia
| | - Kohei M Itoh
- School of Fundamental Science and Technology, Keio University, Yokohama, Japan
| | | | | | - Michael L W Thewalt
- Department of Physics, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Fay E Hudson
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
- Diraq, Sydney, New South Wales, Australia
| | - Andrea Morello
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
| | - Arne Laucht
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
- Diraq, Sydney, New South Wales, Australia
| | - Chih Hwan Yang
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
- Diraq, Sydney, New South Wales, Australia
| | - Andre Saraiva
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia.
- Diraq, Sydney, New South Wales, Australia.
| | - Andrew S Dzurak
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia.
- Diraq, Sydney, New South Wales, Australia.
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37
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Hu X. Highly tunable ultrafast control of a spin qubit. NATURE NANOTECHNOLOGY 2023; 18:100-101. [PMID: 36635332 DOI: 10.1038/s41565-022-01298-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Affiliation(s)
- Xuedong Hu
- Department of Physics, University at Buffalo, SUNY, Buffalo, NY, USA.
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38
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Xie T, Zhao Z, Xu S, Kong X, Yang Z, Wang M, Wang Y, Shi F, Du J. 99.92%-Fidelity cnot Gates in Solids by Noise Filtering. PHYSICAL REVIEW LETTERS 2023; 130:030601. [PMID: 36763408 DOI: 10.1103/physrevlett.130.030601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 12/21/2022] [Indexed: 06/18/2023]
Abstract
Inevitable interactions with the reservoir largely degrade the performance of entangling gates, which hinders practical quantum computation from coming into existence. Here, we experimentally demonstrate a 99.920(7)%-fidelity controlled-not gate by suppressing the complicated noise in a solid-state spin system at room temperature. We found that the fidelity limited at 99% in previous works results from considering only static classical noise, and, thus, in this work, a complete noise model is constructed by also considering the time dependence and the quantum nature of the spin bath. All noises in the model are dynamically corrected by an exquisitely designed shaped pulse, giving the resulting error below 10^{-4}. The residual gate error is mainly originated from the longitudinal relaxation and the waveform distortion that can both be further reduced technically. Our noise-resistant method is universal and will benefit other solid-state spin systems.
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Affiliation(s)
- Tianyu Xie
- CAS Key Laboratory of Microscale Magnetic Resonance and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Zhiyuan Zhao
- CAS Key Laboratory of Microscale Magnetic Resonance and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Shaoyi Xu
- CAS Key Laboratory of Microscale Magnetic Resonance and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Xi Kong
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, China
| | - Zhiping Yang
- CAS Key Laboratory of Microscale Magnetic Resonance and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Mengqi Wang
- CAS Key Laboratory of Microscale Magnetic Resonance and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Ya Wang
- CAS Key Laboratory of Microscale Magnetic Resonance and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
| | - Fazhan Shi
- CAS Key Laboratory of Microscale Magnetic Resonance and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
- School of Biomedical Engineering and Suzhou Institute for Advanced Research, University of Science and Technology of China, Suzhou 215123, China
| | - Jiangfeng Du
- CAS Key Laboratory of Microscale Magnetic Resonance and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
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39
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Zwolak JP, Taylor JM. Colloquium: Advances in automation of quantum dot devices control. REVIEWS OF MODERN PHYSICS 2023; 95:10.1103/revmodphys.95.011006. [PMID: 37051403 PMCID: PMC10088060 DOI: 10.1103/revmodphys.95.011006] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Arrays of quantum dots (QDs) are a promising candidate system to realize scalable, coupled qubit systems and serve as a fundamental building block for quantum computers. In such semiconductor quantum systems, devices now have tens of individual electrostatic and dynamical voltages that must be carefully set to localize the system into the single-electron regime and to realize good qubit operational performance. The mapping of requisite QD locations and charges to gate voltages presents a challenging classical control problem. With an increasing number of QD qubits, the relevant parameter space grows sufficiently to make heuristic control unfeasible. In recent years, there has been considerable effort to automate device control that combines script-based algorithms with machine learning (ML) techniques. In this Colloquium, a comprehensive overview of the recent progress in the automation of QD device control is presented, with a particular emphasis on silicon- and GaAs-based QDs formed in two-dimensional electron gases. Combining physics-based modeling with modern numerical optimization and ML has proven effective in yielding efficient, scalable control. Further integration of theoretical, computational, and experimental efforts with computer science and ML holds vast potential in advancing semiconductor and other platforms for quantum computing.
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Affiliation(s)
| | - Jacob M. Taylor
- Joint Quantum Institute, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
- Joint Center for Quantum Information and Computer Science, University of Maryland, College Park, Maryland 20742, USA
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40
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Kanaar DW, Güngördü U, Kestner JP. Non-adiabatic quantum control of quantum dot arrays with fixed exchange using Cartan decomposition. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2022; 380:20210275. [PMID: 36335944 DOI: 10.1098/rsta.2021.0275] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 09/13/2022] [Indexed: 06/16/2023]
Abstract
In semiconductor spin qubits which typically interact through short-range exchange coupling, shuttling of spin is a practical way to generate quantum operations between distant qubits. Although the exchange is often tunable through voltages applied to gate electrodes, its minimal value can be significantly large, which hinders the applicability of existing shuttling protocols to such devices, requiring a different approach. In this work, we extend our previous results for double- and triple-dot systems, and describe a method for implementing spin state transfer in long chains of singly occupied quantum dots in a non-adiabatic manner. We make use of Cartan decomposition to break down the interacting problem into simpler problems in a systematic way, and use dynamical invariants to design smooth non-adiabatic pulses that can be implemented in devices with modest control bandwidth. Finally, we discuss the extensibility of our results to directed shuttling of spin states on two-dimensional lattices of quantum dots with fixed coupling. This article is part of the theme issue 'Shortcuts to adiabaticity: theoretical, experimental and interdisciplinary perspectives'.
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Affiliation(s)
- David W Kanaar
- Department of Physics, University of Maryland Baltimore County, Baltimore, MD 21250, USA
| | - Utkan Güngördü
- Laboratory for Physical Sciences, College Park, MD 20740, USA
- Department of Physics, University of Maryland, College Park, MD 20742, USA
| | - J P Kestner
- Department of Physics, University of Maryland Baltimore County, Baltimore, MD 21250, USA
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41
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Lu R, Liu K, Ban Y. Robust electron spin qubit control in a nanowire double quantum dot. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2022; 380:20210270. [PMID: 36335949 DOI: 10.1098/rsta.2021.0270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 06/21/2022] [Indexed: 06/16/2023]
Abstract
Robust and efficient manipulation of electron spin qubits in quantum dots is of great significance for the reliable realization of quantum computers and execution of quantum algorithms. In this paper, we study the robust control on a singlet-triplet qubit based on inverse engineering, one technique of shortcuts to adiabaticity (STA), in a nanowire double quantum dot in the presence of magnetic field and strong spin-orbit coupling. The optimization of STA with respect to the systematic errors, contributed from the control field and the perturbative interaction, is explored. Moreover, we also apply optimal control techniques combining with STA, referred to as robust inverse optimization, to design optimal control fields and optimal operation time. This article is part of the theme issue 'Shortcuts to adiabaticity: theoretical, experimental and interdisciplinary perspectives'.
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Affiliation(s)
- Runyu Lu
- School of Materials Science and Engineering, Shanghai University, Shanghai 200444, People's Republic of China
| | - Kaipeng Liu
- International Center of Quantum Artificial Intelligence for Science and Technology (QuArtist) and Department of Physics, Shanghai University, Shanghai 200444, People's Republic of China
| | - Yue Ban
- Department of Physical Chemistry, University of the Basque Country UPV/EHU, Apartado 544, 48080 Bilbao, Spain
- EHU Quantum Center, University of the Basque Country UPV/EHU, Barrio Sarriena, s/n, 48940 Leioa, Biscay, Spain
- TECNALIA, Basque Research and Technology Alliance (BRTA), 48160 Derio, Spain
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42
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Atomic fluctuations lifting the energy degeneracy in Si/SiGe quantum dots. Nat Commun 2022; 13:7730. [PMID: 36513678 PMCID: PMC9747794 DOI: 10.1038/s41467-022-35458-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 12/02/2022] [Indexed: 12/15/2022] Open
Abstract
Electron spins in Si/SiGe quantum wells suffer from nearly degenerate conduction band valleys, which compete with the spin degree of freedom in the formation of qubits. Despite attempts to enhance the valley energy splitting deterministically, by engineering a sharp interface, valley splitting fluctuations remain a serious problem for qubit uniformity, needed to scale up to large quantum processors. Here, we elucidate and statistically predict the valley splitting by the holistic integration of 3D atomic-level properties, theory and transport. We find that the concentration fluctuations of Si and Ge atoms within the 3D landscape of Si/SiGe interfaces can explain the observed large spread of valley splitting from measurements on many quantum dot devices. Against the prevailing belief, we propose to boost these random alloy composition fluctuations by incorporating Ge atoms in the Si quantum well to statistically enhance valley splitting.
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43
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Fang C, Wang Y, Huang S, Brown KR, Kim J. Crosstalk Suppression in Individually Addressed Two-Qubit Gates in a Trapped-Ion Quantum Computer. PHYSICAL REVIEW LETTERS 2022; 129:240504. [PMID: 36563266 DOI: 10.1103/physrevlett.129.240504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 11/16/2022] [Indexed: 06/17/2023]
Abstract
Crosstalk between target and neighboring spectator qubits due to spillover of control signals represents a major error source limiting the fidelity of two-qubit entangling gates in quantum computers. We show that in our laser-driven trapped-ion system coherent crosstalk error can be modeled as residual Xσ[over ^]_{ϕ} interaction and can be actively canceled by single-qubit echoing pulses. We propose and demonstrate a crosstalk suppression scheme that eliminates all first-order crosstalk utilizing only local control of target qubits, as opposed to an existing scheme which requires control over all neighboring qubits. We report a two-qubit Bell state fidelity of 99.52(6)% with the echoing pulses applied after collective gates and 99.37(5)% with the echoing pulses applied to each gate in a five-ion chain. This scheme is widely applicable to other platforms with analogous interaction Hamiltonians.
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Affiliation(s)
- Chao Fang
- Duke Quantum Center, Duke University, Durham, North Carolina 27701, USA
- Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, USA
| | - Ye Wang
- Duke Quantum Center, Duke University, Durham, North Carolina 27701, USA
- Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, USA
| | - Shilin Huang
- Duke Quantum Center, Duke University, Durham, North Carolina 27701, USA
- Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, USA
| | - Kenneth R Brown
- Duke Quantum Center, Duke University, Durham, North Carolina 27701, USA
- Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, USA
- Department of Physics, Duke University, Durham, North Carolina 27708, USA
- Department of Chemistry, Duke University, Durham, North Carolina 27708, USA
| | - Jungsang Kim
- Duke Quantum Center, Duke University, Durham, North Carolina 27701, USA
- Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, USA
- Department of Physics, Duke University, Durham, North Carolina 27708, USA
- IonQ, Inc., College Park, Maryland 20740, USA
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44
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Spin-defect qubits in two-dimensional transition metal dichalcogenides operating at telecom wavelengths. Nat Commun 2022; 13:7501. [PMID: 36473851 PMCID: PMC9723673 DOI: 10.1038/s41467-022-35048-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 11/16/2022] [Indexed: 12/12/2022] Open
Abstract
Solid state quantum defects are promising candidates for scalable quantum information systems which can be seamlessly integrated with the conventional semiconductor electronic devices within the 3D monolithically integrated hybrid classical-quantum devices. Diamond nitrogen-vacancy (NV) center defects are the representative examples, but the controlled positioning of an NV center within bulk diamond is an outstanding challenge. Furthermore, quantum defect properties may not be easily tuned for bulk crystalline quantum defects. In comparison, 2D semiconductors, such as transition metal dichalcogenides (TMDs), are promising solid platform to host a quantum defect with tunable properties and a possibility of position control. Here, we computationally discover a promising defect family for spin qubit realization in 2D TMDs. The defects consist of transition metal atoms substituted at chalcogen sites with desirable spin-triplet ground state, zero-field splitting in the tens of GHz, and strong zero-phonon coupling to optical transitions in the highly desirable telecom band.
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45
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Piot N, Brun B, Schmitt V, Zihlmann S, Michal VP, Apra A, Abadillo-Uriel JC, Jehl X, Bertrand B, Niebojewski H, Hutin L, Vinet M, Urdampilleta M, Meunier T, Niquet YM, Maurand R, Franceschi SD. A single hole spin with enhanced coherence in natural silicon. NATURE NANOTECHNOLOGY 2022; 17:1072-1077. [PMID: 36138200 PMCID: PMC9576591 DOI: 10.1038/s41565-022-01196-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 07/18/2022] [Indexed: 06/16/2023]
Abstract
Semiconductor spin qubits based on spin-orbit states are responsive to electric field excitations, allowing for practical, fast and potentially scalable qubit control. Spin electric susceptibility, however, renders these qubits generally vulnerable to electrical noise, which limits their coherence time. Here we report on a spin-orbit qubit consisting of a single hole electrostatically confined in a natural silicon metal-oxide-semiconductor device. By varying the magnetic field orientation, we reveal the existence of operation sweet spots where the impact of charge noise is minimized while preserving an efficient electric-dipole spin control. We correspondingly observe an extension of the Hahn-echo coherence time up to 88 μs, exceeding by an order of magnitude existing values reported for hole spin qubits, and approaching the state-of-the-art for electron spin qubits with synthetic spin-orbit coupling in isotopically purified silicon. Our finding enhances the prospects of silicon-based hole spin qubits for scalable quantum information processing.
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Affiliation(s)
- N Piot
- Université Grenoble Alpes, CEA, Grenoble INP, IRIG-Pheliqs, Grenoble, France
| | - B Brun
- Université Grenoble Alpes, CEA, Grenoble INP, IRIG-Pheliqs, Grenoble, France.
| | - V Schmitt
- Université Grenoble Alpes, CEA, Grenoble INP, IRIG-Pheliqs, Grenoble, France
| | - S Zihlmann
- Université Grenoble Alpes, CEA, Grenoble INP, IRIG-Pheliqs, Grenoble, France
| | - V P Michal
- Université Grenoble Alpes, CEA, IRIG-MEM-L_Sim, Grenoble, France
| | - A Apra
- Université Grenoble Alpes, CEA, Grenoble INP, IRIG-Pheliqs, Grenoble, France
| | | | - X Jehl
- Université Grenoble Alpes, CEA, Grenoble INP, IRIG-Pheliqs, Grenoble, France
| | - B Bertrand
- Université Grenoble Alpes, CEA, LETI, Minatec Campus, Grenoble, France
| | - H Niebojewski
- Université Grenoble Alpes, CEA, LETI, Minatec Campus, Grenoble, France
| | - L Hutin
- Université Grenoble Alpes, CEA, LETI, Minatec Campus, Grenoble, France
| | - M Vinet
- Université Grenoble Alpes, CEA, LETI, Minatec Campus, Grenoble, France
| | - M Urdampilleta
- Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, Grenoble, France
| | - T Meunier
- Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, Grenoble, France
| | - Y-M Niquet
- Université Grenoble Alpes, CEA, IRIG-MEM-L_Sim, Grenoble, France
| | - R Maurand
- Université Grenoble Alpes, CEA, Grenoble INP, IRIG-Pheliqs, Grenoble, France.
| | - S De Franceschi
- Université Grenoble Alpes, CEA, Grenoble INP, IRIG-Pheliqs, Grenoble, France.
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46
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Noiri A, Takeda K, Nakajima T, Kobayashi T, Sammak A, Scappucci G, Tarucha S. A shuttling-based two-qubit logic gate for linking distant silicon quantum processors. Nat Commun 2022; 13:5740. [PMID: 36180449 PMCID: PMC9525571 DOI: 10.1038/s41467-022-33453-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 09/16/2022] [Indexed: 12/04/2022] Open
Abstract
Control of entanglement between qubits at distant quantum processors using a two-qubit gate is an essential function of a scalable, modular implementation of quantum computation. Among the many qubit platforms, spin qubits in silicon quantum dots are promising for large-scale integration along with their nanofabrication capability. However, linking distant silicon quantum processors is challenging as two-qubit gates in spin qubits typically utilize short-range exchange coupling, which is only effective between nearest-neighbor quantum dots. Here we demonstrate a two-qubit gate between spin qubits via coherent spin shuttling, a key technology for linking distant silicon quantum processors. Coherent shuttling of a spin qubit enables efficient switching of the exchange coupling with an on/off ratio exceeding 1000, while preserving the spin coherence by 99.6% for the single shuttling between neighboring dots. With this shuttling-mode exchange control, we demonstrate a two-qubit controlled-phase gate with a fidelity of 93%, assessed via randomized benchmarking. Combination of our technique and a phase coherent shuttling of a qubit across a large quantum dot array will provide feasible path toward a quantum link between distant silicon quantum processors, a key requirement for large-scale quantum computation. A coherent quantum link between distant quantum processors is desirable for scaling up of quantum computation. Noiri et al. demonstrate a strategy to link distant quantum processors in silicon, by implementing a shuttling-based two-qubit gate between spin qubits in a Si/SiGe triple quantum dot.
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Affiliation(s)
- Akito Noiri
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Japan.
| | - Kenta Takeda
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Japan
| | | | | | - Amir Sammak
- QuTech, Delft University of Technology, Delft, The Netherlands.,Netherlands Organization for Applied Scientific Research (TNO), Delft, The Netherlands
| | - Giordano Scappucci
- QuTech, Delft University of Technology, Delft, The Netherlands.,Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Seigo Tarucha
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Japan. .,RIKEN Center for Quantum Computing (RQC), Wako, Japan.
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47
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Ryu H, Kang JH. Devitalizing noise-driven instability of entangling logic in silicon devices with bias controls. Sci Rep 2022; 12:15200. [PMID: 36071130 PMCID: PMC9452571 DOI: 10.1038/s41598-022-19404-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 08/29/2022] [Indexed: 11/20/2022] Open
Abstract
The quality of quantum bits (qubits) in silicon is highly vulnerable to charge noise that is omnipresent in semiconductor devices and is in principle hard to be suppressed. For a realistically sized quantum dot system based on a silicon-germanium heterostructure whose confinement is manipulated with electrical biases imposed on top electrodes, we computationally explore the noise-robustness of 2-qubit entangling operations with a focus on the controlled-X (CNOT) logic that is essential for designs of gate-based universal quantum logic circuits. With device simulations based on the physics of bulk semiconductors augmented with electronic structure calculations, we not only quantify the degradation in fidelity of single-step CNOT operations with respect to the strength of charge noise, but also discuss a strategy of device engineering that can significantly enhance noise-robustness of CNOT operations with almost no sacrifice of speed compared to the single-step case. Details of device designs and controls that this work presents can establish practical guideline for potential efforts to secure silicon-based quantum processors using an electrode-driven quantum dot platform.
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Affiliation(s)
- Hoon Ryu
- Korea Institute of Science and Technology Information, Daejeon, 34141, Republic of Korea.
| | - Ji-Hoon Kang
- Korea Institute of Science and Technology Information, Daejeon, 34141, Republic of Korea
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Philips SGJ, Mądzik MT, Amitonov SV, de Snoo SL, Russ M, Kalhor N, Volk C, Lawrie WIL, Brousse D, Tryputen L, Wuetz BP, Sammak A, Veldhorst M, Scappucci G, Vandersypen LMK. Universal control of a six-qubit quantum processor in silicon. Nature 2022; 609:919-924. [PMID: 36171383 PMCID: PMC9519456 DOI: 10.1038/s41586-022-05117-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 07/15/2022] [Indexed: 11/25/2022]
Abstract
Future quantum computers capable of solving relevant problems will require a large number of qubits that can be operated reliably1. However, the requirements of having a large qubit count and operating with high fidelity are typically conflicting. Spins in semiconductor quantum dots show long-term promise2,3 but demonstrations so far use between one and four qubits and typically optimize the fidelity of either single- or two-qubit operations, or initialization and readout4-11. Here, we increase the number of qubits and simultaneously achieve respectable fidelities for universal operation, state preparation and measurement. We design, fabricate and operate a six-qubit processor with a focus on careful Hamiltonian engineering, on a high level of abstraction to program the quantum circuits, and on efficient background calibration, all of which are essential to achieve high fidelities on this extended system. State preparation combines initialization by measurement and real-time feedback with quantum-non-demolition measurements. These advances will enable testing of increasingly meaningful quantum protocols and constitute a major stepping stone towards large-scale quantum computers.
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Affiliation(s)
- Stephan G J Philips
- QuTech and the Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands
| | - Mateusz T Mądzik
- QuTech and the Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands
| | - Sergey V Amitonov
- QuTech and the Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands
| | - Sander L de Snoo
- QuTech and the Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands
| | - Maximilian Russ
- QuTech and the Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands
| | - Nima Kalhor
- QuTech and the Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands
| | - Christian Volk
- QuTech and the Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands
| | - William I L Lawrie
- QuTech and the Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands
| | - Delphine Brousse
- QuTech and Netherlands Organization for Applied Scientific Research (TNO), Delft, the Netherlands
| | - Larysa Tryputen
- QuTech and Netherlands Organization for Applied Scientific Research (TNO), Delft, the Netherlands
| | - Brian Paquelet Wuetz
- QuTech and the Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands
| | - Amir Sammak
- QuTech and Netherlands Organization for Applied Scientific Research (TNO), Delft, the Netherlands
| | - Menno Veldhorst
- QuTech and the Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands
| | - Giordano Scappucci
- QuTech and the Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands
| | - Lieven M K Vandersypen
- QuTech and the Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands.
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49
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Takeda K, Noiri A, Nakajima T, Kobayashi T, Tarucha S. Quantum error correction with silicon spin qubits. Nature 2022; 608:682-686. [PMID: 36002485 PMCID: PMC9402442 DOI: 10.1038/s41586-022-04986-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 06/16/2022] [Indexed: 11/09/2022]
Abstract
Future large-scale quantum computers will rely on quantum error correction (QEC) to protect the fragile quantum information during computation1,2. Among the possible candidate platforms for realizing quantum computing devices, the compatibility with mature nanofabrication technologies of silicon-based spin qubits offers promise to overcome the challenges in scaling up device sizes from the prototypes of today to large-scale computers3-5. Recent advances in silicon-based qubits have enabled the implementations of high-quality one-qubit and two-qubit systems6-8. However, the demonstration of QEC, which requires three or more coupled qubits1, and involves a three-qubit gate9-11 or measurement-based feedback, remains an open challenge. Here we demonstrate a three-qubit phase-correcting code in silicon, in which an encoded three-qubit state is protected against any phase-flip error on one of the three qubits. The correction to this encoded state is performed by a three-qubit conditional rotation, which we implement by an efficient single-step resonantly driven iToffoli gate. As expected, the error correction mitigates the errors owing to one-qubit phase-flip, as well as the intrinsic dephasing mainly owing to quasi-static phase noise. These results show successful implementation of QEC and the potential of a silicon-based platform for large-scale quantum computing.
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Affiliation(s)
- Kenta Takeda
- Center for Emergent Matter Science (CEMS), RIKEN, Wako, Japan.
| | - Akito Noiri
- Center for Emergent Matter Science (CEMS), RIKEN, Wako, Japan
| | | | | | - Seigo Tarucha
- Center for Emergent Matter Science (CEMS), RIKEN, Wako, Japan.
- Center for Quantum Computing (RQC), RIKEN, Wako, Japan.
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50
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Surface code for low-density qubit array. Sci Rep 2022; 12:12946. [PMID: 35902709 PMCID: PMC9334604 DOI: 10.1038/s41598-022-17090-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 07/20/2022] [Indexed: 11/20/2022] Open
Abstract
Surface code is a promising candidate for the quantum error corrections needed for fault-tolerant quantum computations because it can operate on a two-dimensional grid of qubits. However, the gates and control lines become dense as more and more qubits are integrated, making their design and control difficult. This problem can be alleviated if the surface code can operate on sparse qubit arrays. Here, we give an solution for an array in which qubits are placed on edges as well as on nodes of a two-dimensional grid. The qubits on the edges are divided into two groups: those in one group act as the deputies of data qubits; the others act as deputies of the syndrome qubits. Syndrome outputs are obtained by multiplying the measured values of the syndrome and edge qubits. The procedure for the quantum part is the same as that of the ordinary surface code, making the surface code applicable to sparse qubit arrays.
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