1
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Zhang Y, Guan H, Sheng T, Chen R, Rogge S, Du J, Yin C. Fast Thermodynamic Study on a Silicon Nanotransistor at Cryogenic Temperatures. NANO LETTERS 2024; 24:8859-8865. [PMID: 38981024 DOI: 10.1021/acs.nanolett.4c01424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2024]
Abstract
Cryogenic temperatures are crucial for the operation of semiconductor quantum electronic devices, yet the heating effects induced by microwave or laser signals used for quantum state manipulation can lead to significant temperature variations at the nanoscale. Therefore, probing the temperature of individual devices in working conditions and understanding the thermodynamics are paramount for designing and operating large-scale quantum computing systems. In this study, we demonstrate high-sensitivity fast thermometry in a silicon nanotransistor at cryogenic temperatures using RF reflectometry. Through this method, we explore the thermodynamic processes of the nanotransistor during and after a laser pulse and determine the dominant heat dissipation channels in the few-kelvin temperature range. These insights are important to understand thermal budgets in quantum circuits, with our techniques being compatible with microwave and laser radiation, offering a versatile approach for studying other quantum electronic devices in working conditions.
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Affiliation(s)
- Yangbo Zhang
- 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
| | - Hao Guan
- 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
| | - Tingfeng Sheng
- 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
| | - Ruiwen Chen
- 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
| | - Sven Rogge
- Centre of Excellence for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, NSW 2052, Australia
| | - 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
| | - Chunming Yin
- 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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2
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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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3
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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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4
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Zou J, Bosco S, Loss D. Spatially correlated classical and quantum noise in driven qubits. NPJ QUANTUM INFORMATION 2024; 10:46. [PMID: 38706554 PMCID: PMC11062932 DOI: 10.1038/s41534-024-00842-9] [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: 08/27/2023] [Accepted: 04/17/2024] [Indexed: 05/07/2024]
Abstract
Correlated noise across multiple qubits poses a significant challenge for achieving scalable and fault-tolerant quantum processors. Despite recent experimental efforts to quantify this noise in various qubit architectures, a comprehensive understanding of its role in qubit dynamics remains elusive. Here, we present an analytical study of the dynamics of driven qubits under spatially correlated noise, including both Markovian and non-Markovian noise. Surprisingly, we find that by operating the qubit system at low temperatures, where correlated quantum noise plays an important role, significant long-lived entanglement between qubits can be generated. Importantly, this generation process can be controlled on-demand by turning the qubit driving on and off. On the other hand, we demonstrate that by operating the system at a higher temperature, the crosstalk between qubits induced by the correlated noise is unexpectedly suppressed. We finally reveal the impact of spatio-temporally correlated 1/f noise on the decoherence rate, and how its temporal correlations restore lost entanglement. Our findings provide critical insights into not only suppressing crosstalk between qubits caused by correlated noise but also in effectively leveraging such noise as a beneficial resource for controlled entanglement generation.
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Affiliation(s)
- Ji Zou
- Department of Physics, University of Basel, Basel, Switzerland
| | - Stefano Bosco
- Department of Physics, University of Basel, Basel, Switzerland
| | - Daniel Loss
- Department of Physics, University of Basel, Basel, Switzerland
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5
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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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6
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Wu PY, Lee WQ, Liu CH, Huang CB. Coherent control of enhanced second-harmonic generation in a plasmonic nanocircuit using a transition metal dichalcogenide monolayer. Nat Commun 2024; 15:1855. [PMID: 38424147 PMCID: PMC10904783 DOI: 10.1038/s41467-024-46209-8] [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: 10/31/2023] [Accepted: 02/19/2024] [Indexed: 03/02/2024] Open
Abstract
Nonlinear nanophotonic circuits, renowned for their compact form and integration capabilities, hold potential for advancing high-capacity optical signal processing. However, limited practicality arises from low nonlinear conversion efficiency. Transition metal dichalcogenides (TMDs) could present a promising avenue to address this challenge, given their superior optical nonlinear characteristics and compatibility with diverse device platforms. Nevertheless, this potential remains largely unexplored, with current endeavors predominantly focusing on the demonstration of TMDs' coherent nonlinear signals via free-space excitation and collection. In this work, we perform direct integration of TMDs onto a plasmonic nanocircuitry. By controlling the polarization angle of the input laser, we show selective routing of second-harmonic generation (SHG) signals from a MoSe2 monolayer within the plasmonic circuit. Routing extinction ratios of 14.86 dB are achieved, demonstrating good coherence preservation in this hybrid nanocircuit. Additionally, our characterization indicates that the integration of TMDs leads to a 13.8-fold SHG enhancement, compared with the pristine nonlinear plasmonic nanocircuitry. These distinct features-efficient SHG generation, coupling, and controllable routing-suggest that our hybrid TMD-plasmonic nanocircuitry could find immediate applications including on-chip optical frequency conversion, selective routing, switching, logic operations, as well as quantum operations.
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Affiliation(s)
- Pei-Yuan Wu
- Institute of Photonics Technologies, National Tsing Hua University, Hsinchu, Taiwan
| | - Wei-Qing Lee
- Institute of Photonics Technologies, National Tsing Hua University, Hsinchu, Taiwan
| | - Chang-Hua Liu
- Institute of Photonics Technologies, National Tsing Hua University, Hsinchu, Taiwan.
| | - Chen-Bin Huang
- Institute of Photonics Technologies, National Tsing Hua University, Hsinchu, Taiwan.
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7
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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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8
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Ungerer JH, Sarmah D, Kononov A, Ridderbos J, Haller R, Cheung LY, Schönenberger C. Performance of high impedance resonators in dirty dielectric environments. EPJ QUANTUM TECHNOLOGY 2023; 10:41. [PMID: 37810533 PMCID: PMC10558395 DOI: 10.1140/epjqt/s40507-023-00199-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 09/27/2023] [Indexed: 10/10/2023]
Abstract
High-impedance resonators are a promising contender for realizing long-distance entangling gates between spin qubits. Often, the fabrication of spin qubits relies on the use of gate dielectrics which are detrimental to the quality of the resonator. Here, we investigate loss mechanisms of high-impedance NbTiN resonators in the vicinity of thermally grown SiO2 and Al2O3 fabricated by atomic layer deposition. We benchmark the resonator performance in elevated magnetic fields and at elevated temperatures and find that the internal quality factors are limited by the coupling between the resonator and two-level systems of the employed oxides. Nonetheless, the internal quality factors of high-impedance resonators exceed 103 in all investigated oxide configurations which implies that the dielectric configuration would not limit the performance of resonators integrated in a spin-qubit device. Because these oxides are commonly used for spin qubit device fabrication, our results allow for straightforward integration of high-impedance resonators into spin-based quantum processors. Hence, these experiments pave the way for large-scale, spin-based quantum computers.
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Affiliation(s)
- J. H. Ungerer
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
- Swiss Nanoscience Institute, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| | - D. Sarmah
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| | - A. Kononov
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| | - J. Ridderbos
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
- Present Address: NanoElectronics Group, MESA Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - R. Haller
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| | - L. Y. Cheung
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| | - C. Schönenberger
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
- Swiss Nanoscience Institute, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
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9
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Liu H, Wang K, Gao F, Leng J, Liu Y, Zhou YC, Cao G, Wang T, Zhang J, Huang P, Li HO, Guo GP. Ultrafast and Electrically Tunable Rabi Frequency in a Germanium Hut Wire Hole Spin Qubit. NANO LETTERS 2023; 23:3810-3817. [PMID: 37098786 DOI: 10.1021/acs.nanolett.3c00213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Hole spin qubits based on germanium (Ge) have strong tunable spin-orbit interaction (SOI) and ultrafast qubit operation speed. Here we report that the Rabi frequency (fRabi) of a hole spin qubit in a Ge hut wire (HW) double quantum dot (DQD) is electrically tuned through the detuning energy (ϵ) and middle gate voltage (VM). fRabi gradually decreases with increasing ϵ; on the contrary, fRabi is positively correlated with VM. We attribute our results to the change of electric field on SOI and the contribution of the excited state in quantum dots to fRabi. We further demonstrate an ultrafast fRabi exceeding 1.2 GHz, which indicates the strong SOI in our device. The discovery of an ultrafast and electrically tunable fRabi in a hole spin qubit has potential applications in semiconductor quantum computing.
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Affiliation(s)
- He Liu
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 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 and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Fei Gao
- Institute of Physics and CAS Center for Excellence in Topological Quantum Computation, Chinese Academy of Sciences, Beijing 100190, China
- Qilu Institute of Technology, Jinan 250200, China
| | - Jin Leng
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Yang Liu
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Yu-Chen Zhou
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 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 and Synergetic Innovation Center 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
| | - Ting Wang
- Institute of Physics and CAS Center for Excellence in Topological Quantum Computation, Chinese Academy of Sciences, Beijing 100190, China
- Hefei National Laboratory, University of Science and Technology of China, 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, University of Science and Technology of China, Hefei 230088, China
| | - Peihao Huang
- Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- International Quantum Academy, Shenzhen 518048, China
- Guangdong Provincial Key Laboratory of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Hai-Ou Li
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center for Excellence and Synergetic Innovation Center 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
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center for Excellence and Synergetic Innovation Center 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 230026, China
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10
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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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11
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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)
- Justyna P. Zwolak
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - 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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12
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Hybrid classical-quantum machine learning based on dissipative two-qubit channels. Sci Rep 2022; 12:20440. [DOI: 10.1038/s41598-022-24346-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 11/14/2022] [Indexed: 11/29/2022] Open
Abstract
AbstractAlthough the environmental effects, i.e., dissipation and decoherence seem to be the strongest adversaries in the quantum information realm, here, we address how dissipation can be harnessed for quantum state preparation and universal quantum computation. In this line, we propose a realistic scheme for hybrid classical-quantum neural networks based on dissipative two-qubit channels. In particular, we design a variational quantum circuit consisting of a set of universal quantum gates. We encode classical information in the initial states of a two-qubit system interacting with a global environment. This composite system plays the role of a dissipative quantum channel (DQC). A pooling layer concatenates the output states of the DQCs resulting in the outcome of the circuit. Both the DCQs and the pooling layer provide superposition and entanglement which are the key ingredients of any universal quantum computation protocol. Finally, we investigate the capability and adaptability of this model by doing some machine learning tasks. It is reasonable to postulate that a quantum computer based on DQCs may outperform a classical computer because, in contrast to the latter, the former is capable of producing atypical patterns through non-classical phenomena.
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13
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Park J, Zhou JJ, Luo Y, Bernardi M. Predicting Phonon-Induced Spin Decoherence from First Principles: Colossal Spin Renormalization in Condensed Matter. PHYSICAL REVIEW LETTERS 2022; 129:197201. [PMID: 36399728 DOI: 10.1103/physrevlett.129.197201] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 08/11/2022] [Indexed: 06/16/2023]
Abstract
Developing a microscopic understanding of spin decoherence is essential to advancing quantum technologies. Electron spin decoherence due to atomic vibrations (phonons) plays a special role as it sets an intrinsic limit to the performance of spin-based quantum devices. Two main sources of phonon-induced spin decoherence-the Elliott-Yafet and Dyakonov-Perel mechanisms-have distinct physical origins and theoretical treatments. Here, we show calculations that unify their modeling and enable accurate predictions of spin relaxation and precession in semiconductors. We compute the phonon-dressed vertex of the spin-spin correlation function with a treatment analogous to the calculation of the anomalous electron magnetic moment in QED. We find that the vertex correction provides a giant renormalization of the electron spin dynamics in solids, greater by many orders of magnitude than the corresponding correction from photons in vacuum. Our Letter demonstrates a general approach for quantitative analysis of spin decoherence in materials, advancing the quest for spin-based quantum technologies.
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Affiliation(s)
- Jinsoo Park
- Department of Applied Physics and Materials Science, California Institute of Technology, Pasadena, California 91125, USA
| | - Jin-Jian Zhou
- School of Physics, Beijing Institute of Technology, Beijing 100081, China
| | - Yao Luo
- Department of Applied Physics and Materials Science, California Institute of Technology, Pasadena, California 91125, USA
| | - Marco Bernardi
- Department of Physics, California Institute of Technology, Pasadena, California 91125, USA
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14
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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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15
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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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16
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Ercan HE, Friesen M, Coppersmith SN. Charge-Noise Resilience of Two-Electron Quantum Dots in Si/SiGe Heterostructures. PHYSICAL REVIEW LETTERS 2022; 128:247701. [PMID: 35776472 DOI: 10.1103/physrevlett.128.247701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 03/30/2022] [Accepted: 04/07/2022] [Indexed: 06/15/2023]
Abstract
The valley degree of freedom presents challenges and opportunities for silicon spin qubits. An important consideration for singlet-triplet states is the presence of two distinct triplets, composed of valley vs orbital excitations. Here, we show that both of these triplets are present in the typical operating regime, but that only the valley-excited triplet offers intrinsic protection against charge noise. We further show that this protection arises naturally in dots with stronger confinement. These results reveal an inherent advantage for silicon-based multielectron qubits.
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Affiliation(s)
- H Ekmel Ercan
- Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Mark Friesen
- Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - S N Coppersmith
- Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
- School of Physics, The University of New South Wales, Sydney, New South Wales 2052, Australia
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17
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Levonian DS, Riedinger R, Machielse B, Knall EN, Bhaskar MK, Knaut CM, Bekenstein R, Park H, Lončar M, Lukin MD. Optical Entanglement of Distinguishable Quantum Emitters. PHYSICAL REVIEW LETTERS 2022; 128:213602. [PMID: 35687460 DOI: 10.1103/physrevlett.128.213602] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 03/21/2022] [Indexed: 06/15/2023]
Abstract
Solid-state quantum emitters are promising candidates for the realization of quantum networks, owing to their long-lived spin memories, high-fidelity local operations, and optical connectivity for long-range entanglement. However, due to differences in local environment, solid-state emitters typically feature a range of distinct transition frequencies, which makes it challenging to create optically mediated entanglement between arbitrary emitter pairs. We propose and demonstrate an efficient method for entangling emitters with optical transitions separated by many linewidths. In our approach, electro-optic modulators enable a single photon to herald a parity measurement on a pair of spin qubits. We experimentally demonstrate the protocol using two silicon-vacancy centers in a diamond nanophotonic cavity, with optical transitions separated by 7.4 GHz. Working with distinguishable emitters allows for individual qubit addressing and readout, enabling parallel control and entanglement of both colocated and spatially separated emitters, a key step toward scaling up quantum information processing systems.
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Affiliation(s)
- D S Levonian
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- AWS Center for Quantum Computing, Pasadena, California 91125, USA
| | - R Riedinger
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Institut für Laserphysik und Zentrum für Optische Quantentechnologien, Universität Hamburg, 22761 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging, 22761 Hamburg, Germany
| | - B Machielse
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- AWS Center for Quantum Computing, Pasadena, California 91125, USA
| | - E N Knall
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
| | - M K Bhaskar
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- AWS Center for Quantum Computing, Pasadena, California 91125, USA
| | - C M Knaut
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - R Bekenstein
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - H Park
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
| | - M Lončar
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
| | - M D Lukin
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
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18
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Choi Y, Adamczyk AJ. Competitive Hydrogen Migration in Silicon Nitride Nanoclusters: Reaction Kinetics Generalized from Supervised Machine Learning. J Phys Chem A 2022; 126:2677-2689. [PMID: 35452242 DOI: 10.1021/acs.jpca.2c01050] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The rate coefficients for 52 hydrogen shift reactions for silicon nitrides containing up to 6 atoms of silicon and nitrogen have been calculated using the G3//B3LYP composite method and statistical thermodynamics. The overall reaction of substituted acyclic and cyclic silylenes to their respective silene and imine species by a 1,2-hydrogen shift reaction was sorted by three different types of H shift reactions using overall reaction thermodynamics: (1) endothermic H shift between N and Si:, (2) endothermic H shift between Si and Si:, and (3) exothermic H shift between Si and Si:. Endothermic H shift reactions between Si atoms have one dominant activation barrier where the exothermic H shift reaction between Si atoms has two barriers and a stable intermediate. The rate-determining step was determined to be from the intermediate to the substituted silene, and then kinetic parameters for the overall reaction were calculated for the two-step pathway. The single event pre-exponential factors, Ã, and activation energies, Ea, for the three different classes of hydrogen shift reactions of silicon nitrides were computed. The hydrogen shift reaction was explored for acyclic and cyclic monofunctional silicon nitrides, and the type of hydrogen shift reaction gives the most significant influence on the kinetic parameters. Using a supervised machine learning approach, the models for predicting the energy barrier of three different hydrogen shift reactions were generalized and suggested based on selected descriptors.
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Affiliation(s)
- Yeseul Choi
- Department of Chemical Engineering, Auburn University, 212 Ross Hall, Auburn, Alabama 36830, United States
| | - Andrew J Adamczyk
- Department of Chemical Engineering, Auburn University, 212 Ross Hall, Auburn, Alabama 36830, United States
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19
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Single electrons on solid neon as a solid-state qubit platform. Nature 2022; 605:46-50. [PMID: 35508782 DOI: 10.1038/s41586-022-04539-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 02/09/2022] [Indexed: 11/08/2022]
Abstract
Progress towards the realization of quantum computers requires persistent advances in their constituent building blocks-qubits. Novel qubit platforms that simultaneously embody long coherence, fast operation and large scalability offer compelling advantages in the construction of quantum computers and many other quantum information systems1-3. Electrons, ubiquitous elementary particles of non-zero charge, spin and mass, have commonly been perceived as paradigmatic local quantum information carriers. Despite superior controllability and configurability, their practical performance as qubits through either motional or spin states depends critically on their material environment3-5. Here we report our experimental realization of a qubit platform based on isolated single electrons trapped on an ultraclean solid neon surface in vacuum6-13. By integrating an electron trap in a circuit quantum electrodynamics architecture14-20, we achieve strong coupling between the motional states of a single electron and a single microwave photon in an on-chip superconducting resonator. Qubit gate operations and dispersive readout are implemented to measure the energy relaxation time T1 of 15 μs and phase coherence time T2 over 200 ns. These results indicate that the electron-on-solid-neon qubit already performs near the state of the art for a charge qubit21.
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20
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Lodari M, Lampert L, Zietz O, Pillarisetty R, Clarke JS, Scappucci G. Valley Splitting in Silicon from the Interference Pattern of Quantum Oscillations. PHYSICAL REVIEW LETTERS 2022; 128:176603. [PMID: 35570466 DOI: 10.1103/physrevlett.128.176603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 04/05/2022] [Indexed: 06/15/2023]
Abstract
We determine the energy splitting of the conduction-band valleys in two-dimensional electrons confined in silicon metal oxide semiconductor Hall-bar transistors. These silicon metal oxide semiconductor Hall bars are made by advanced semiconductor manufacturing on 300 mm silicon wafers and support a two-dimensional electron gas of high quality with a maximum mobility of 17.6×10^{3} cm^{2}/Vs and minimum percolation density of 3.45×10^{10} cm^{-2}. Because of the low disorder, we observe beatings in the Shubnikov-de Haas oscillations that arise from the energy splitting of the two low-lying conduction band valleys. From the analysis of the oscillations beating patterns up to T=1.7 K, we estimate a maximum valley splitting of ΔE_{VS}=8.2 meV at a density of 6.8×10^{12} cm^{-2}. Furthermore, the valley splitting increases with density at a rate consistent with theoretical predictions for a near-ideal semiconductor-oxide interface.
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Affiliation(s)
- M Lodari
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, Post Office Box 5046, 2600 GA Delft, Netherlands
| | - L Lampert
- Intel Components Research, Intel Corporation, 2501 NW 229th Avenue, Hillsboro, Oregon 97124, USA
| | - O Zietz
- Intel Components Research, Intel Corporation, 2501 NW 229th Avenue, Hillsboro, Oregon 97124, USA
| | - R Pillarisetty
- Intel Components Research, Intel Corporation, 2501 NW 229th Avenue, Hillsboro, Oregon 97124, USA
| | - J S Clarke
- Intel Components Research, Intel Corporation, 2501 NW 229th Avenue, Hillsboro, Oregon 97124, USA
| | - G Scappucci
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, Post Office Box 5046, 2600 GA Delft, Netherlands
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21
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Connors EJ, Nelson J, Edge LF, Nichol JM. Charge-noise spectroscopy of Si/SiGe quantum dots via dynamically-decoupled exchange oscillations. Nat Commun 2022; 13:940. [PMID: 35177606 PMCID: PMC8854405 DOI: 10.1038/s41467-022-28519-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 01/26/2022] [Indexed: 11/23/2022] Open
Abstract
Electron spins in silicon quantum dots are promising qubits due to their long coherence times, scalable fabrication, and potential for all-electrical control. However, charge noise in the host semiconductor presents a major obstacle to achieving high-fidelity single- and two-qubit gates in these devices. In this work, we measure the charge-noise spectrum of a Si/SiGe singlet-triplet qubit over nearly 12 decades in frequency using a combination of methods, including dynamically-decoupled exchange oscillations with up to 512 π pulses during the qubit evolution. The charge noise is colored across the entire frequency range of our measurements, although the spectral exponent changes with frequency. Moreover, the charge-noise spectrum inferred from conductance measurements of a proximal sensor quantum dot agrees with that inferred from coherent oscillations of the singlet-triplet qubit, suggesting that simple transport measurements can accurately characterize the charge noise over a wide frequency range in Si/SiGe quantum dots.
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Affiliation(s)
- Elliot J Connors
- Department of Physics and Astronomy, University of Rochester, Rochester, NY, 14627, USA
| | - J Nelson
- Department of Physics and Astronomy, University of Rochester, Rochester, NY, 14627, USA
| | - Lisa F Edge
- HRL Laboratories LLC, 3011 Malibu Canyon Road, Malibu, CA, 90265, USA
| | - John M Nichol
- Department of Physics and Astronomy, University of Rochester, Rochester, NY, 14627, USA.
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22
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Abstract
Today, an electron spin qubit on silicon appears to be a very promising physical platform for the fabrication of future quantum microprocessors. Thousands of these qubits should be packed together into one single silicon die in order to break the quantum supremacy barrier. Microelectronics engineers are currently leveraging on the current CMOS technology to design the manipulation and read-out electronics as cryogenic integrated circuits. Several of these circuits are RFICs, as VCO, LNA, and mixers. Therefore, the availability of a qubit CAD model plays a central role in the proper design of these cryogenic RFICs. The present paper reports on a circuit-based compact model of an electron spin qubit for CAD applications. The proposed model is described and tested, and the limitations faced are highlighted and discussed.
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23
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A silicon singlet-triplet qubit driven by spin-valley coupling. Nat Commun 2022; 13:641. [PMID: 35110561 PMCID: PMC8810768 DOI: 10.1038/s41467-022-28302-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 12/22/2021] [Indexed: 11/25/2022] Open
Abstract
Spin–orbit effects, inherent to electrons confined in quantum dots at a silicon heterointerface, provide a means to control electron spin qubits without the added complexity of on-chip, nanofabricated micromagnets or nearby coplanar striplines. Here, we demonstrate a singlet–triplet qubit operating mode that can drive qubit evolution at frequencies in excess of 200 MHz. This approach offers a means to electrically turn on and off fast control, while providing high logic gate orthogonality and long qubit dephasing times. We utilize this operational mode for dynamical decoupling experiments to probe the charge noise power spectrum in a silicon metal-oxide-semiconductor double quantum dot. In addition, we assess qubit frequency drift over longer timescales to capture low-frequency noise. We present the charge noise power spectral density up to 3 MHz, which exhibits a 1/fα dependence consistent with α ~ 0.7, over 9 orders of magnitude in noise frequency. Spin-orbit coupling in gate-defined quantum dots in silicon metal-oxide semiconductors provides a promising route for electrical control of spin qubits. Here, the authors demonstrate that intervalley spin–orbit interaction enables fast singlet–triplet qubit rotations in this platform, at frequencies exceeding 200MHz.
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24
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Noiri A, Takeda K, Nakajima T, Kobayashi T, Sammak A, Scappucci G, Tarucha S. Fast universal quantum gate above the fault-tolerance threshold in silicon. Nature 2022; 601:338-342. [PMID: 35046603 DOI: 10.1038/s41586-021-04182-y] [Citation(s) in RCA: 50] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 10/26/2021] [Indexed: 11/09/2022]
Abstract
Fault-tolerant quantum computers that can solve hard problems rely on quantum error correction1. One of the most promising error correction codes is the surface code2, which requires universal gate fidelities exceeding an error correction threshold of 99 per cent3. Among the many qubit platforms, only superconducting circuits4, trapped ions5 and nitrogen-vacancy centres in diamond6 have delivered this requirement. Electron spin qubits in silicon7-15 are particularly promising for a large-scale quantum computer owing to their nanofabrication capability, but the two-qubit gate fidelity has been limited to 98 per cent owing to the slow operation16. Here we demonstrate a two-qubit gate fidelity of 99.5 per cent, along with single-qubit gate fidelities of 99.8 per cent, in silicon spin qubits by fast electrical control using a micromagnet-induced gradient field and a tunable two-qubit coupling. We identify the qubit rotation speed and coupling strength where we robustly achieve high-fidelity gates. We realize Deutsch-Jozsa and Grover search algorithms with high success rates using our universal gate set. Our results demonstrate universal gate fidelity beyond the fault-tolerance threshold and may enable scalable silicon quantum computers.
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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 Organisation 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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25
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Ultrafast coherent control of a hole spin qubit in a germanium quantum dot. Nat Commun 2022; 13:206. [PMID: 35017522 PMCID: PMC8752786 DOI: 10.1038/s41467-021-27880-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 12/16/2021] [Indexed: 11/23/2022] Open
Abstract
Operation speed and coherence time are two core measures for the viability of a qubit. Strong spin-orbit interaction (SOI) and relatively weak hyperfine interaction make holes in germanium (Ge) intriguing candidates for spin qubits with rapid, all-electrical coherent control. Here we report ultrafast single-spin manipulation in a hole-based double quantum dot in a germanium hut wire (GHW). Mediated by the strong SOI, a Rabi frequency exceeding 540 MHz is observed at a magnetic field of 100 mT, setting a record for ultrafast spin qubit control in semiconductor systems. We demonstrate that the strong SOI of heavy holes (HHs) in our GHW, characterized by a very short spin-orbit length of 1.5 nm, enables the rapid gate operations we accomplish. Our results demonstrate the potential of ultrafast coherent control of hole spin qubits to meet the requirement of DiVincenzo’s criteria for a scalable quantum information processor. Hole-spin qubits in germanium are promising candidates for rapid, all-electrical qubit control. Here the authors report Rabi oscillations with the record frequency of 540 MHz in a hole-based double quantum dot in a germanium hut wire, which is attributed to strong spin-orbit interaction of heavy holes.
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26
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Jia Z, Fu Y, Cao Z, Cheng W, Zhao Y, Dou M, Duan P, Kong W, Cao G, Li H, Guo G. Superconducting and Silicon-Based Semiconductor Quantum Computers: A Review. IEEE NANOTECHNOLOGY MAGAZINE 2022. [DOI: 10.1109/mnano.2022.3175394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Zhilong Jia
- University of Science and Technology of China
| | - Yaobin Fu
- Hefei Origin Quantum Computing Technology
| | - Zhen Cao
- Hefei Origin Quantum Computing Technology
| | | | | | | | - Peng Duan
- University of Science and Technology of China
| | | | - Gang Cao
- University of Science and Technology of China
| | - Haiou Li
- University of Science and Technology of China
| | - Guoping Guo
- University of Science and Technology of China
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27
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Vinet M. The path to scalable quantum computing with silicon spin qubits. NATURE NANOTECHNOLOGY 2021; 16:1296-1298. [PMID: 34887536 DOI: 10.1038/s41565-021-01037-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Affiliation(s)
- Maud Vinet
- CEA Leti, Université Grenoble Alpes, Grenoble, France.
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28
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Nikandish R, Blokhina E, Leipold D, Staszewski RB. Semiconductor Quantum Computing: Toward a CMOS quantum computer on chip. IEEE NANOTECHNOLOGY MAGAZINE 2021. [DOI: 10.1109/mnano.2021.3113216] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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29
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Hu RZ, Ma RL, Ni M, Zhang X, Zhou Y, Wang K, Luo G, Cao G, Kong ZZ, Wang GL, Li HO, Guo GP. An Operation Guide of Si-MOS Quantum Dots for Spin Qubits. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:2486. [PMID: 34684927 PMCID: PMC8540968 DOI: 10.3390/nano11102486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 09/13/2021] [Accepted: 09/18/2021] [Indexed: 11/23/2022]
Abstract
In the last 20 years, silicon quantum dots have received considerable attention from academic and industrial communities for research on readout, manipulation, storage, near-neighbor and long-range coupling of spin qubits. In this paper, we introduce how to realize a single spin qubit from Si-MOS quantum dots. First, we introduce the structure of a typical Si-MOS quantum dot and the experimental setup. Then, we show the basic properties of the quantum dot, including charge stability diagram, orbital state, valley state, lever arm, electron temperature, tunneling rate and spin lifetime. After that, we introduce the two most commonly used methods for spin-to-charge conversion, i.e., Elzerman readout and Pauli spin blockade readout. Finally, we discuss the details of how to find the resonance frequency of spin qubits and show the result of coherent manipulation, i.e., Rabi oscillation. The above processes constitute an operation guide for helping the followers enter the field of spin qubits in Si-MOS quantum dots.
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Affiliation(s)
- Rui-Zi Hu
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China; (R.-Z.H.); (R.-L.M.); (M.N.); (X.Z.); (Y.Z.); (K.W.); (G.L.); (G.C.); (G.-P.G.)
- CAS Center for Excellence and Synergetic Innovation Center 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 230026, China; (R.-Z.H.); (R.-L.M.); (M.N.); (X.Z.); (Y.Z.); (K.W.); (G.L.); (G.C.); (G.-P.G.)
- CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Ming Ni
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China; (R.-Z.H.); (R.-L.M.); (M.N.); (X.Z.); (Y.Z.); (K.W.); (G.L.); (G.C.); (G.-P.G.)
- CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Xin Zhang
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China; (R.-Z.H.); (R.-L.M.); (M.N.); (X.Z.); (Y.Z.); (K.W.); (G.L.); (G.C.); (G.-P.G.)
- CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Yuan Zhou
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China; (R.-Z.H.); (R.-L.M.); (M.N.); (X.Z.); (Y.Z.); (K.W.); (G.L.); (G.C.); (G.-P.G.)
- CAS Center for Excellence and Synergetic Innovation Center 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 230026, China; (R.-Z.H.); (R.-L.M.); (M.N.); (X.Z.); (Y.Z.); (K.W.); (G.L.); (G.C.); (G.-P.G.)
- CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Gang Luo
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China; (R.-Z.H.); (R.-L.M.); (M.N.); (X.Z.); (Y.Z.); (K.W.); (G.L.); (G.C.); (G.-P.G.)
- CAS Center for Excellence and Synergetic Innovation Center 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 230026, China; (R.-Z.H.); (R.-L.M.); (M.N.); (X.Z.); (Y.Z.); (K.W.); (G.L.); (G.C.); (G.-P.G.)
- CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Zhen-Zhen Kong
- Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China;
| | - Gui-Lei Wang
- Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China;
| | - Hai-Ou Li
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China; (R.-Z.H.); (R.-L.M.); (M.N.); (X.Z.); (Y.Z.); (K.W.); (G.L.); (G.C.); (G.-P.G.)
- CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Guo-Ping Guo
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China; (R.-Z.H.); (R.-L.M.); (M.N.); (X.Z.); (Y.Z.); (K.W.); (G.L.); (G.C.); (G.-P.G.)
- CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
- Origin Quantum Computing Company Limited, Hefei 230026, China
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30
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Corrigan J, Dodson JP, Ercan HE, Abadillo-Uriel JC, Thorgrimsson B, Knapp TJ, Holman N, McJunkin T, Neyens SF, MacQuarrie ER, Foote RH, Edge LF, Friesen M, Coppersmith SN, Eriksson MA. Coherent Control and Spectroscopy of a Semiconductor Quantum Dot Wigner Molecule. PHYSICAL REVIEW LETTERS 2021; 127:127701. [PMID: 34597063 DOI: 10.1103/physrevlett.127.127701] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 07/19/2021] [Indexed: 06/13/2023]
Abstract
Semiconductor quantum dots containing more than one electron have found wide application in qubits, where they enable readout and enhance polarizability. However, coherent control in such dots has typically been restricted to only the lowest two levels, and such control in the strongly interacting regime has not been realized. Here we report quantum control of eight different transitions in a silicon-based quantum dot. We use qubit readout to perform spectroscopy, revealing a dense set of energy levels with characteristic spacing far smaller than the single-particle energy. By comparing with full configuration interaction calculations, we argue that the dense set of levels arises from Wigner-molecule physics.
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Affiliation(s)
- J Corrigan
- University of Wisconsin, Madison, Wisconsin 53706, USA
| | - J P Dodson
- University of Wisconsin, Madison, Wisconsin 53706, USA
| | - H Ekmel Ercan
- University of Wisconsin, Madison, Wisconsin 53706, USA
| | | | | | - T J Knapp
- University of Wisconsin, Madison, Wisconsin 53706, USA
| | - Nathan Holman
- University of Wisconsin, Madison, Wisconsin 53706, USA
| | | | | | | | - Ryan H Foote
- University of Wisconsin, Madison, Wisconsin 53706, USA
| | - L F Edge
- HRL Laboratories, LLC, 3011 Malibu Canyon Road, Malibu, California 90265, USA
| | - Mark Friesen
- University of Wisconsin, Madison, Wisconsin 53706, USA
| | - S N Coppersmith
- University of Wisconsin, Madison, Wisconsin 53706, USA
- University of New South Wales, Sydney, NSW 2052, Australia
| | - M A Eriksson
- University of Wisconsin, Madison, Wisconsin 53706, USA
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31
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Kato K, Liu Y, Murakami S, Morita Y, Mori T. Electron beam lithography with negative tone resist for highly integrated silicon quantum bits. NANOTECHNOLOGY 2021; 32:485301. [PMID: 34425562 DOI: 10.1088/1361-6528/ac201b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 08/23/2021] [Indexed: 06/13/2023]
Abstract
Process technologies have been developed for electron-beam (EB) lithography aimed at silicon quantum devices and their large-scale integration. It is necessary to understand the proximity effect and construct a method for its correction to perform EB lithography of fine and complicated structures. In this study, we investigate the lithography of Si quantum devices with a point-beam EB system and a maN 2401 negative tone resist, in order to correspond to various types of device structures. We optimize temperatures for specialized pre- and post-exposure bakes for forming ∼20 nm fine patterns with small line-edge roughness. Further, we demonstrated the fabrication of Si-on-insulator device patterns that have some tiny dots connected with many large wires/pads in the layout, with the careful tuning of the dose assignment. In this tuning, we used the EB process simulation to estimate the cumulative dose distribution effectively. In addition, we reproduced the experimentally obtained resist patterns via the EB process simulation after considering the mid-range effect, which is a factors in the proximity effect but is not yet deeply understood. The results of this study are expected to provide useful process technologies for EB lithography, which will help drastically accelerate the research on Si quantum devices with a high degree of freedom.
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Affiliation(s)
- Kimihiko Kato
- National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1, Umezono, Tsukuba, Ibaraki 305-8568, Japan
| | - Yongxun Liu
- National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1, Umezono, Tsukuba, Ibaraki 305-8568, Japan
| | - Shigenori Murakami
- National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1, Umezono, Tsukuba, Ibaraki 305-8568, Japan
| | - Yukinori Morita
- National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1, Umezono, Tsukuba, Ibaraki 305-8568, Japan
| | - Takahiro Mori
- National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1, Umezono, Tsukuba, Ibaraki 305-8568, Japan
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32
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Takeda K, Noiri A, Nakajima T, Yoneda J, Kobayashi T, Tarucha S. Quantum tomography of an entangled three-qubit state in silicon. NATURE NANOTECHNOLOGY 2021; 16:965-969. [PMID: 34099899 DOI: 10.1038/s41565-021-00925-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Accepted: 04/30/2021] [Indexed: 06/12/2023]
Abstract
Quantum entanglement is a fundamental property of coherent quantum states and an essential resource for quantum computing1. In large-scale quantum systems, the error accumulation requires concepts for quantum error correction. A first step toward error correction is the creation of genuinely multipartite entanglement, which has served as a performance benchmark for quantum computing platforms such as superconducting circuits2,3, trapped ions4 and nitrogen-vacancy centres in diamond5. Among the candidates for large-scale quantum computing devices, silicon-based spin qubits offer an outstanding nanofabrication capability for scaling-up. Recent studies demonstrated improved coherence times6-8, high-fidelity all-electrical control9-13, high-temperature operation14,15 and quantum entanglement of two spin qubits9,11,12. Here we generated a three-qubit Greenberger-Horne-Zeilinger state using a low-disorder, fully controllable array of three spin qubits in silicon. We performed quantum state tomography16 and obtained a state fidelity of 88.0%. The measurements witness a genuine Greenberger-Horne-Zeilinger class quantum entanglement that cannot be separated into any biseparable state. Our results showcase the potential of silicon-based spin qubit platforms for multiqubit quantum algorithms.
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Affiliation(s)
- Kenta Takeda
- Center for Emergent Matter Science (CEMS), RIKEN, Wako-shi, Saitama, Japan.
| | - Akito Noiri
- Center for Emergent Matter Science (CEMS), RIKEN, Wako-shi, Saitama, Japan
| | - Takashi Nakajima
- Center for Emergent Matter Science (CEMS), RIKEN, Wako-shi, Saitama, Japan
| | - Jun Yoneda
- Center for Emergent Matter Science (CEMS), RIKEN, Wako-shi, Saitama, Japan
- Tokyo Tech Academy for Super Smart Society, Tokyo Institute of Technology, Tokyo, Japan
| | - Takashi Kobayashi
- Center for Emergent Matter Science (CEMS), RIKEN, Wako-shi, Saitama, Japan
| | - Seigo Tarucha
- Center for Emergent Matter Science (CEMS), RIKEN, Wako-shi, Saitama, Japan.
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33
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Vahapoglu E, Slack-Smith JP, Leon RCC, Lim WH, Hudson FE, Day T, Tanttu T, Yang CH, Laucht A, Dzurak AS, Pla JJ. Single-electron spin resonance in a nanoelectronic device using a global field. SCIENCE ADVANCES 2021; 7:7/33/eabg9158. [PMID: 34389538 PMCID: PMC8363148 DOI: 10.1126/sciadv.abg9158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 06/23/2021] [Indexed: 06/13/2023]
Abstract
Spin-based silicon quantum electronic circuits offer a scalable platform for quantum computation, combining the manufacturability of semiconductor devices with the long coherence times afforded by spins in silicon. Advancing from current few-qubit devices to silicon quantum processors with upward of a million qubits, as required for fault-tolerant operation, presents several unique challenges, one of the most demanding being the ability to deliver microwave signals for large-scale qubit control. Here, we demonstrate a potential solution to this problem by using a three-dimensional dielectric resonator to broadcast a global microwave signal across a quantum nanoelectronic circuit. Critically, this technique uses only a single microwave source and is capable of delivering control signals to millions of qubits simultaneously. We show that the global field can be used to perform spin resonance of single electrons confined in a silicon double quantum dot device, establishing the feasibility of this approach for scalable spin qubit control.
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Affiliation(s)
- Ensar Vahapoglu
- School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, NSW 2052, Australia.
| | - James P Slack-Smith
- School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, NSW 2052, Australia.
| | - Ross C C Leon
- School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Wee Han Lim
- School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Fay E Hudson
- School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Tom Day
- School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Tuomo Tanttu
- School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Chih Hwan Yang
- School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Arne Laucht
- School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Andrew S Dzurak
- School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, NSW 2052, Australia.
| | - Jarryd J Pla
- School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, NSW 2052, Australia.
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34
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Huang JY, Lim WH, Leon RCC, Yang CH, Hudson FE, Escott CC, Saraiva A, Dzurak AS, Laucht A. A High-Sensitivity Charge Sensor for Silicon Qubits above 1 K. NANO LETTERS 2021; 21:6328-6335. [PMID: 33999635 DOI: 10.1021/acs.nanolett.1c01003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Recent studies of silicon spin qubits at temperatures above 1 K are encouraging demonstrations that the cooling requirements for solid-state quantum computing can be considerably relaxed. However, qubit readout mechanisms that rely on charge sensing with a single-island single-electron transistor (SISET) quickly lose sensitivity due to thermal broadening of the electron distribution in the reservoirs. Here we exploit the tunneling between two quantized states in a double-island single-electron transistor (SET) to demonstrate a charge sensor with an improvement in the signal-to-noise ratio by an order of magnitude compared to a standard SISET, and a single-shot charge readout fidelity above 99% up to 8 K at a bandwidth greater than 100 kHz. These improvements are consistent with our theoretical modeling of the temperature-dependent current transport for both types of SETs. With minor additional hardware overhead, these sensors can be integrated into existing qubit architectures for a high-fidelity charge readout at few-kelvin temperatures.
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Affiliation(s)
- Jonathan Yue Huang
- Centre for Quantum Computation & Communication Technology, School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney 2052, Australia
| | - Wee Han Lim
- Centre for Quantum Computation & Communication Technology, School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney 2052, Australia
| | - Ross C C Leon
- Centre for Quantum Computation & Communication Technology, School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney 2052, Australia
| | - Chih Hwan Yang
- Centre for Quantum Computation & Communication Technology, School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney 2052, Australia
| | - Fay E Hudson
- Centre for Quantum Computation & Communication Technology, School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney 2052, Australia
| | - Christopher C Escott
- Centre for Quantum Computation & Communication Technology, School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney 2052, Australia
| | - Andre Saraiva
- Centre for Quantum Computation & Communication Technology, School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney 2052, Australia
| | - Andrew S Dzurak
- Centre for Quantum Computation & Communication Technology, School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney 2052, Australia
| | - Arne Laucht
- Centre for Quantum Computation & Communication Technology, School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney 2052, Australia
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35
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Yoneda J, Huang W, Feng M, Yang CH, Chan KW, Tanttu T, Gilbert W, Leon RCC, Hudson FE, Itoh KM, Morello A, Bartlett SD, Laucht A, Saraiva A, Dzurak AS. Coherent spin qubit transport in silicon. Nat Commun 2021; 12:4114. [PMID: 34226564 PMCID: PMC8257656 DOI: 10.1038/s41467-021-24371-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 05/23/2021] [Indexed: 11/09/2022] Open
Abstract
A fault-tolerant quantum processor may be configured using stationary qubits interacting only with their nearest neighbours, but at the cost of significant overheads in physical qubits per logical qubit. Such overheads could be reduced by coherently transporting qubits across the chip, allowing connectivity beyond immediate neighbours. Here we demonstrate high-fidelity coherent transport of an electron spin qubit between quantum dots in isotopically-enriched silicon. We observe qubit precession in the inter-site tunnelling regime and assess the impact of qubit transport using Ramsey interferometry and quantum state tomography techniques. We report a polarization transfer fidelity of 99.97% and an average coherent transfer fidelity of 99.4%. Our results provide key elements for high-fidelity, on-chip quantum information distribution, as long envisaged, reinforcing the scaling prospects of silicon-based spin qubits.
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Affiliation(s)
- J Yoneda
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, Australia. .,Tokyo Tech Academy for Super Smart Society, Tokyo Institute of Technology, Tokyo, Japan.
| | - W Huang
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, Australia.,Solid State Physics Laboratory, ETH Zurich, Zurich, Switzerland
| | - M Feng
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, Australia
| | - C H Yang
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, Australia
| | - K W Chan
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, Australia
| | - T Tanttu
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, Australia
| | - W Gilbert
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, Australia
| | - R C C Leon
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, Australia
| | - F E Hudson
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, Australia
| | - K M Itoh
- School of Fundamental Science and Technology, Keio University, Yokohama, Japan
| | - A Morello
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, Australia
| | - S D Bartlett
- Centre for Engineered Quantum Systems, School of Physics, University of Sydney, Sydney, NSW, Australia
| | - A Laucht
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, Australia
| | - A Saraiva
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, Australia
| | - A S Dzurak
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, Australia.
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36
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CMOS-based cryogenic control of silicon quantum circuits. Nature 2021; 593:205-210. [PMID: 33981049 DOI: 10.1038/s41586-021-03469-4] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 03/18/2021] [Indexed: 11/08/2022]
Abstract
The most promising quantum algorithms require quantum processors that host millions of quantum bits when targeting practical applications1. A key challenge towards large-scale quantum computation is the interconnect complexity. In current solid-state qubit implementations, an important interconnect bottleneck appears between the quantum chip in a dilution refrigerator and the room-temperature electronics. Advanced lithography supports the fabrication of both control electronics and qubits in silicon using technology compatible with complementary metal oxide semiconductors (CMOS)2. When the electronics are designed to operate at cryogenic temperatures, they can ultimately be integrated with the qubits on the same die or package, overcoming the 'wiring bottleneck'3-6. Here we report a cryogenic CMOS control chip operating at 3 kelvin, which outputs tailored microwave bursts to drive silicon quantum bits cooled to 20 millikelvin. We first benchmark the control chip and find an electrical performance consistent with qubit operations of 99.99 per cent fidelity, assuming ideal qubits. Next, we use it to coherently control actual qubits encoded in the spin of single electrons confined in silicon quantum dots7-9 and find that the cryogenic control chip achieves the same fidelity as commercial instruments at room temperature. Furthermore, we demonstrate the capabilities of the control chip by programming a number of benchmarking protocols, as well as the Deutsch-Josza algorithm10, on a two-qubit quantum processor. These results open up the way towards a fully integrated, scalable silicon-based quantum computer.
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37
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Sauter E, Abrosimov NV, Hübner J, Oestreich M. Low Temperature Relaxation of Donor Bound Electron Spins in ^{28}Si:P. PHYSICAL REVIEW LETTERS 2021; 126:137402. [PMID: 33861119 DOI: 10.1103/physrevlett.126.137402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 03/08/2021] [Indexed: 06/12/2023]
Abstract
We measure the spin-lattice relaxation of donor bound electrons in ultrapure, isotopically enriched, phosphorus-doped ^{28}Si:P. The optical pump-probe experiments reveal at low temperatures extremely long spin relaxation times which exceed 20 h. The ^{28}Si:P spin relaxation rate increases linearly with temperature in the regime below 1 K and shows a distinct transition to a T^{9} dependence which dominates the spin relaxation between 2 and 4 K at low magnetic fields. The T^{7} dependence reported for natural silicon is absent. At high magnetic fields, the spin relaxation is dominated by the magnetic field dependent single phonon spin relaxation process. This process is well documented for natural silicon at finite temperatures but the ^{28}Si:P measurements validate additionally that the bosonic phonon distribution leads at very low temperatures to a deviation from the linear temperature dependence of Γ as predicted by theory.
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Affiliation(s)
- E Sauter
- Institut für Festkörperphysik, Leibniz Universität Hannover, 30167 Hannover, Germany
| | - N V Abrosimov
- Leibniz-Institut für Kristallzüchtung, 12489 Berlin, Germany
| | - J Hübner
- Institut für Festkörperphysik, Leibniz Universität Hannover, 30167 Hannover, Germany
| | - M Oestreich
- Institut für Festkörperphysik, Leibniz Universität Hannover, 30167 Hannover, Germany
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38
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Abstract
The prospect of building quantum circuits1,2 using advanced semiconductor manufacturing makes quantum dots an attractive platform for quantum information processing3,4. Extensive studies of various materials have led to demonstrations of two-qubit logic in gallium arsenide5, silicon6-12 and germanium13. However, interconnecting larger numbers of qubits in semiconductor devices has remained a challenge. Here we demonstrate a four-qubit quantum processor based on hole spins in germanium quantum dots. Furthermore, we define the quantum dots in a two-by-two array and obtain controllable coupling along both directions. Qubit logic is implemented all-electrically and the exchange interaction can be pulsed to freely program one-qubit, two-qubit, three-qubit and four-qubit operations, resulting in a compact and highly connected circuit. We execute a quantum logic circuit that generates a four-qubit Greenberger-Horne-Zeilinger state and we obtain coherent evolution by incorporating dynamical decoupling. These results are a step towards quantum error correction and quantum simulation using quantum dots.
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39
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Chan KW, Sahasrabudhe H, Huang W, Wang Y, Yang HC, Veldhorst M, Hwang JCC, Mohiyaddin FA, Hudson FE, Itoh KM, Saraiva A, Morello A, Laucht A, Rahman R, Dzurak AS. Exchange Coupling in a Linear Chain of Three Quantum-Dot Spin Qubits in Silicon. NANO LETTERS 2021; 21:1517-1522. [PMID: 33481612 DOI: 10.1021/acs.nanolett.0c04771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Quantum gates between spin qubits can be implemented leveraging the natural Heisenberg exchange interaction between two electrons in contact with each other. This interaction is controllable by electrically tailoring the overlap between electronic wave functions in quantum dot systems, as long as they occupy neighboring dots. An alternative route is the exploration of superexchange-the coupling between remote spins mediated by a third idle electron that bridges the distance between quantum dots. We experimentally demonstrate direct exchange coupling and provide evidence for second neighbor mediated superexchange in a linear array of three single-electron spin qubits in silicon, inferred from the electron spin resonance frequency spectra. We confirm theoretically, through atomistic modeling, that the device geometry only allows for sizable direct exchange coupling for neighboring dots, while next-nearest neighbor coupling cannot stem from the vanishingly small tail of the electronic wave function of the remote dots, and is only possible if mediated.
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Affiliation(s)
- Kok Wai Chan
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Harshad Sahasrabudhe
- Department of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Wister Huang
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Yu Wang
- Department of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Henry C Yang
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Menno Veldhorst
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Jason C C Hwang
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Fahd A Mohiyaddin
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Fay E Hudson
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Kohei M Itoh
- School of Fundamental Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan
| | - Andre Saraiva
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Andrea Morello
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Arne Laucht
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Rajib Rahman
- Department of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- School of Physics, The University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Andrew S Dzurak
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales 2052, Australia
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40
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Santanni F, Albino A, Atzori M, Ranieri D, Salvadori E, Chiesa M, Lunghi A, Bencini A, Sorace L, Totti F, Sessoli R. Probing Vibrational Symmetry Effects and Nuclear Spin Economy Principles in Molecular Spin Qubits. Inorg Chem 2021; 60:140-151. [PMID: 33305944 PMCID: PMC7872321 DOI: 10.1021/acs.inorgchem.0c02573] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Indexed: 12/18/2022]
Abstract
The selection of molecular spin qubits with a long coherence time, Tm, is a central task for implementing molecule-based quantum technologies. Even if a sufficiently long Tm can be achieved through an efficient synthetic strategy and ad hoc experimental measurement procedures, many factors contributing to the loss of coherence still need to be thoroughly investigated and understood. Vibrational properties and nuclear spins of hydrogens are two of them. The former plays a paramount role, but a detailed theoretical investigation aimed at studying their effects on the spin dynamics of molecular complexes such as the benchmark phthalocyanine (Pc) is still missing, whereas the effect of the latter deserves to be examined in detail for such a class of compounds. In this work, we adopted a combined theoretical and experimental approach to investigate the relaxation properties of classical [Cu(Pc)] and a CuII complex based on the ligand tetrakis(thiadiazole)porphyrazine (H2TTDPz), characterized by a hydrogen-free molecular structure. Systematic calculations of molecular vibrations exemplify the effect of normal modes on the spin-lattice relaxation process, unveiling a different contribution to T1 depending on the symmetry of normal modes. Moreover, we observed that an appreciable Tm enhancement could be achieved by removing hydrogens from the ligand.
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Affiliation(s)
- Fabio Santanni
- Dipartimento
di Chimica “Ugo Schiff” & INSTM RU, Università degli Studi di Firenze, Via della Lastruccia 3, I50019 Sesto Fiorentino, Firenze) Italy
| | - Andrea Albino
- Dipartimento
di Chimica “Ugo Schiff” & INSTM RU, Università degli Studi di Firenze, Via della Lastruccia 3, I50019 Sesto Fiorentino, Firenze) Italy
| | - Matteo Atzori
- Laboratoire
National des Champs Magnétiques Intenses (LNCMI), Univ. Grenoble
Alpes, INSA Toulouse, Univ. Toulouse Paul
Sabatier, EMFL, CNRS, F38043 Grenoble, France
| | - Davide Ranieri
- Dipartimento
di Chimica “Ugo Schiff” & INSTM RU, Università degli Studi di Firenze, Via della Lastruccia 3, I50019 Sesto Fiorentino, Firenze) Italy
| | - Enrico Salvadori
- Dipartimento
di Chimica e NIS Centre, Università
di Torino, Via P. Giuria 7, I10125 Torino, Italy
| | - Mario Chiesa
- Dipartimento
di Chimica e NIS Centre, Università
di Torino, Via P. Giuria 7, I10125 Torino, Italy
| | - Alessandro Lunghi
- School
of Physics, AMBER and CRANN Institute, Trinity
College, Dublin 2, Ireland
| | - Andrea Bencini
- Dipartimento
di Chimica “Ugo Schiff” & INSTM RU, Università degli Studi di Firenze, Via della Lastruccia 3, I50019 Sesto Fiorentino, Firenze) Italy
| | - Lorenzo Sorace
- Dipartimento
di Chimica “Ugo Schiff” & INSTM RU, Università degli Studi di Firenze, Via della Lastruccia 3, I50019 Sesto Fiorentino, Firenze) Italy
| | - Federico Totti
- Dipartimento
di Chimica “Ugo Schiff” & INSTM RU, Università degli Studi di Firenze, Via della Lastruccia 3, I50019 Sesto Fiorentino, Firenze) Italy
| | - Roberta Sessoli
- Dipartimento
di Chimica “Ugo Schiff” & INSTM RU, Università degli Studi di Firenze, Via della Lastruccia 3, I50019 Sesto Fiorentino, Firenze) Italy
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Abstract
The spin of a single electron in a semiconductor quantum dot provides a well-controlled and long-lived qubit implementation. The electron charge in turn allows control of the position of individual electrons in a quantum dot array, and enables charge sensors to probe the charge configuration. Here we show that the Coulomb repulsion allows an initial charge transition to induce subsequent charge transitions, inducing a cascade of electron hops, like toppling dominoes. A cascade can transmit information along a quantum dot array over a distance that extends by far the effect of the direct Coulomb repulsion. We demonstrate that a cascade of electrons can be combined with Pauli spin blockade to read out distant spins and show results with potential for high fidelity using a remote charge sensor in a quadruple quantum dot device. We implement and analyse several operating modes for cascades and analyse their scaling behaviour. We also discuss the application of cascade-based spin readout to densely-packed two-dimensional quantum dot arrays with charge sensors placed at the periphery. The high connectivity of such arrays greatly improves the capabilities of quantum dot systems for quantum computation and simulation. Readout of remote spins in quantum dot arrays is a challenge for future quantum computing architectures. Here, the authors implement electron cascade for spin readout on quantum dots far away from a charge sensor in a quadruple quantum dot device and discuss its applicability to large-scale arrays.
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42
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Stein RM, Barcikowski ZS, Pookpanratana SJ, Pomeroy JM, Stewart MD. Alternatives to aluminum gates for silicon quantum devices: defects and strain. JOURNAL OF APPLIED PHYSICS 2021; 130:10.1063/5.0036520. [PMID: 36733463 PMCID: PMC9890375 DOI: 10.1063/5.0036520] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 02/16/2021] [Indexed: 06/13/2023]
Abstract
Gate-defined quantum dots (QD) benefit from the use of small grain size metals for gate materials because it aids in shrinking the device dimensions. However, it is not clear what differences arise with respect to process-induced defect densities and inhomogeneous strain. Here, we present measurements of fixed charge, Q f , interface trap density, D it , the intrinsic film stress, σ, and the coefficient of thermal expansion, α as a function of forming gas anneal temperature for Al, Ti/Pd, and Ti/Pt gates. We show D it is minimal at an anneal temperature of 350 °C for all materials but Ti/Pd and Ti/Pt have higher Q f and D it compared to Al. In addition, σ and α increase with anneal temperature for all three metals with α larger than the bulk value. These results indicate that there is a tradeoff between minimizing defects and minimizing the impact of strain in quantum device fabrication.
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Affiliation(s)
- Ryan M. Stein
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA
| | - Z. S. Barcikowski
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA
| | - S. J. Pookpanratana
- National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - J. M. Pomeroy
- National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - M. D. Stewart
- National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
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43
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Bardin JC, Slichter DH, Reilly DJ. Microwaves in Quantum Computing. IEEE JOURNAL OF MICROWAVES 2021; 1:10.1109/JMW.2020.3034071. [PMID: 34355217 PMCID: PMC8335598 DOI: 10.1109/jmw.2020.3034071] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Quantum information processing systems rely on a broad range of microwave technologies and have spurred development of microwave devices and methods in new operating regimes. Here we review the use of microwave signals and systems in quantum computing, with specific reference to three leading quantum computing platforms: trapped atomic ion qubits, spin qubits in semiconductors, and superconducting qubits. We highlight some key results and progress in quantum computing achieved through the use of microwave systems, and discuss how quantum computing applications have pushed the frontiers of microwave technology in some areas. We also describe open microwave engineering challenges for the construction of large-scale, fault-tolerant quantum computers.
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Affiliation(s)
- Joseph C Bardin
- Department of Electrical and Computer Engineering, University of Massachusetts Amherst, Amherst, MA 01003 USA
- Google LLC, Goleta, CA 93117 USA
| | - Daniel H Slichter
- Time and Frequency Division, National Institute of Standards and Technology, Boulder, CO 80305 USA
| | - David J Reilly
- Microsoft Inc., Microsoft Quantum Sydney, The University of Sydney, Sydney, NSW 2050, Australia
- ARC Centre of Excellence for Engineered Quantum Systems (EQuS), School of Physics, The University of Sydney, Sydney, NSW 2050, Australia
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44
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Zhang ZZ, Hu Q, Song XX, Ying Y, Li HO, Zhang Z, Guo GP. A Suspended Silicon Single-Hole Transistor as an Extremely Scaled Gigahertz Nanoelectromechanical Beam Resonator. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2005625. [PMID: 33191506 DOI: 10.1002/adma.202005625] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 10/27/2020] [Indexed: 06/11/2023]
Abstract
Suspended single-hole transistors (SHTs) can also serve as nanoelectromechanical resonators, providing an ideal platform for investigating interactions between mechanical vibrations and charge carriers. Demonstrating such a device in silicon (Si) is of particular interest, due to the strong piezoresistive effect of Si and potential applications in Si-based quantum computation. Here, a suspended Si SHT also acting as a nanoelectromechanical beam resonator is demonstrated. The resonant frequency and zero-point motion of the device are ≈3 GHz and 0.2 pm, respectively, reaching the best level among similar devices demonstrated with Si-containing materials. The mechanical vibration is transduced to electrical readout by the SHT. The signal transduction mechanism is dominated by the piezoresistive effect. A giant apparent effective piezoresistive gauge factor with strong correlation to single-hole tunneling is extracted in this device. The results show the great potential of the device in interfacing charge carriers with mechanical vibrations, as well as investigating potential quantum behavior of the vibration phonon mode.
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Affiliation(s)
- Zhuo-Zhi Zhang
- CAS Key Laboratory of Quantum Information, CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Qitao Hu
- Division of Solid-State Electronics, Department of Electrical Engineering, Uppsala University, Uppsala, 75237, Sweden
| | - Xiang-Xiang Song
- CAS Key Laboratory of Quantum Information, CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Yue Ying
- CAS Key Laboratory of Quantum Information, CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Hai-Ou Li
- CAS Key Laboratory of Quantum Information, CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Zhen Zhang
- Division of Solid-State Electronics, Department of Electrical Engineering, Uppsala University, Uppsala, 75237, Sweden
| | - Guo-Ping Guo
- CAS Key Laboratory of Quantum Information, CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China
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45
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Wuetz BP, Losert MP, Tosato A, Lodari M, Bavdaz PL, Stehouwer L, Amin P, Clarke JS, Coppersmith SN, Sammak A, Veldhorst M, Friesen M, Scappucci G. Effect of Quantum Hall Edge Strips on Valley Splitting in Silicon Quantum Wells. PHYSICAL REVIEW LETTERS 2020; 125:186801. [PMID: 33196242 DOI: 10.1103/physrevlett.125.186801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 09/23/2020] [Indexed: 06/11/2023]
Abstract
We determine the energy splitting of the conduction-band valleys in two-dimensional electrons confined to low-disorder Si quantum wells. We probe the valley splitting dependence on both perpendicular magnetic field B and Hall density by performing activation energy measurements in the quantum Hall regime over a large range of filling factors. The mobility gap of the valley-split levels increases linearly with B and is strikingly independent of Hall density. The data are consistent with a transport model in which valley splitting depends on the incremental changes in density eB/h across quantum Hall edge strips, rather than the bulk density. Based on these results, we estimate that the valley splitting increases with density at a rate of 116 μeV/10^{11} cm^{-2}, which is consistent with theoretical predictions for near-perfect quantum well top interfaces.
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Affiliation(s)
- Brian Paquelet Wuetz
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA Delft, Netherlands
| | | | - Alberto Tosato
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA Delft, Netherlands
| | - Mario Lodari
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA Delft, Netherlands
| | - Peter L Bavdaz
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA Delft, Netherlands
| | - Lucas Stehouwer
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA Delft, Netherlands
| | - Payam Amin
- Components Research, Intel Corporation, 2501 NW 229th Ave, Hillsboro, Oregon 97124, USA
| | - James S Clarke
- Components Research, Intel Corporation, 2501 NW 229th Ave, Hillsboro, Oregon 97124, USA
| | | | - Amir Sammak
- QuTech and Netherlands Organisation for Applied Scientific Research (TNO), Stieltjesweg 1, 2628 CK Delft, Netherlands
| | - Menno Veldhorst
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA Delft, Netherlands
| | - Mark Friesen
- University of Wisconsin-Madison, Madison, Wisconsin 53706 USA
| | - Giordano Scappucci
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA Delft, Netherlands
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46
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Lawrie WIL, Hendrickx NW, van Riggelen F, Russ M, Petit L, Sammak A, Scappucci G, Veldhorst M. Spin Relaxation Benchmarks and Individual Qubit Addressability for Holes in Quantum Dots. NANO LETTERS 2020; 20:7237-7242. [PMID: 32833455 PMCID: PMC7564448 DOI: 10.1021/acs.nanolett.0c02589] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 08/24/2020] [Indexed: 06/11/2023]
Abstract
We investigate hole spin relaxation in the single- and multihole regime in a 2 × 2 germanium quantum dot array. We find spin relaxation times T1 as high as 32 and 1.2 ms for quantum dots with single- and five-hole occupations, respectively, setting benchmarks for spin relaxation times for hole quantum dots. Furthermore, we investigate qubit addressability and electric field sensitivity by measuring resonance frequency dependence of each qubit on gate voltages. We can tune the resonance frequency over a large range for both single and multihole qubits, while simultaneously finding that the resonance frequencies are only weakly dependent on neighboring gates. In particular, the five-hole qubit resonance frequency is more than 20 times as sensitive to its corresponding plunger gate. Excellent individual qubit tunability and long spin relaxation times make holes in germanium promising for addressable and high-fidelity spin qubits in dense two-dimensional quantum dot arrays for large-scale quantum information.
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Affiliation(s)
- W. I. L. Lawrie
- QuTech
and Kavli Institute of Nanoscience, Delft
University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - N. W. Hendrickx
- QuTech
and Kavli Institute of Nanoscience, Delft
University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - F. van Riggelen
- QuTech
and Kavli Institute of Nanoscience, Delft
University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - M. Russ
- QuTech
and Kavli Institute of Nanoscience, Delft
University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - L. Petit
- QuTech
and Kavli Institute of Nanoscience, Delft
University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - A. Sammak
- QuTech
and Netherlands Organization for Applied Scientific Research (TNO), Stieltjesweg 1, 2628 CK Delft, The Netherlands
| | - G. Scappucci
- QuTech
and Kavli Institute of Nanoscience, Delft
University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - M. Veldhorst
- QuTech
and Kavli Institute of Nanoscience, Delft
University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
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47
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Kranz L, Gorman SK, Thorgrimsson B, He Y, Keith D, Keizer JG, Simmons MY. Exploiting a Single-Crystal Environment to Minimize the Charge Noise on Qubits in Silicon. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2003361. [PMID: 32830388 DOI: 10.1002/adma.202003361] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 07/22/2020] [Accepted: 07/27/2020] [Indexed: 06/11/2023]
Abstract
Electron spins in silicon offer a competitive, scalable quantum-computing platform with excellent single-qubit properties. However, the two-qubit gate fidelities achieved so far have fallen short of the 99% threshold required for large-scale error-corrected quantum computing architectures. In the past few years, there has been a growing realization that the critical obstacle in meeting this threshold in semiconductor qubits is charge noise arising from the qubit environment. In this work, a notably low level of charge noise of S0 = 0.0088 ± 0.0004 μeV2 Hz-1 is demonstrated using atom qubits in crystalline silicon, achieved by separating the qubits from surfaces and interface states. The charge noise is measured using both a single electron transistor and an exchange-coupled qubit pair that collectively provide a consistent charge noise spectrum over four frequency decades, with the noise level S0 being an order of magnitude lower than previously reported. Low-frequency detuning noise, set by the total measurement time, is shown to be the dominant dephasing source of two-qubit exchange oscillations. With recent advances in fast (≈μs) single-shot readout, it is shown that by reducing the total measurement time to ≈1 s, 99.99% two-qubit S W A P gate fidelities can be achieved in single-crystal atom qubits in silicon.
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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, NSW, 2052, Australia
- Silicon Quantum Computing Pty Ltd., Level 2, Newton Building, UNSW Sydney, Kensington, NSW, 2052, Australia
| | - Samuel Keith Gorman
- Centre of Excellence for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, NSW, 2052, Australia
- Silicon Quantum Computing Pty Ltd., Level 2, Newton Building, UNSW Sydney, Kensington, NSW, 2052, Australia
| | - Brandur Thorgrimsson
- Centre of Excellence for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, NSW, 2052, Australia
- Silicon Quantum Computing Pty Ltd., Level 2, Newton Building, UNSW Sydney, Kensington, NSW, 2052, Australia
| | - Yu He
- Centre of Excellence for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Daniel Keith
- Centre of Excellence for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Joris Gerhard Keizer
- Centre of Excellence for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, NSW, 2052, Australia
- Silicon Quantum Computing Pty Ltd., Level 2, Newton Building, UNSW Sydney, Kensington, NSW, 2052, Australia
| | - Michelle Yvonne Simmons
- Centre of Excellence for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, NSW, 2052, Australia
- Silicon Quantum Computing Pty Ltd., Level 2, Newton Building, UNSW Sydney, Kensington, NSW, 2052, Australia
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48
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Gunasekaran S, Reed DA, Paley DW, Bartholomew AK, Venkataraman L, Steigerwald ML, Roy X, Nuckolls C. Single-Electron Currents in Designer Single-Cluster Devices. J Am Chem Soc 2020; 142:14924-14932. [PMID: 32809814 DOI: 10.1021/jacs.0c04970] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Atomically precise clusters can be used to create single-electron devices wherein a single redox-active cluster is connected to two macroscopic electrodes via anchoring ligands. Unlike single-electron devices comprising nanocrystals, these cluster-based devices can be fabricated with atomic precision. This affords an unprecedented level of control over the device properties. Herein, we design a series of cobalt chalcogenide clusters with varying ligand geometries and core nuclearities to control their current-voltage (I-V) characteristics in a scanning tunneling microscope-based break junction (STM-BJ) device. First, the device geometry is modified by precisely positioning junction-anchoring ligands on the surface of the cluster. We show that the I-V characteristics are independent of ligand placement, confirming a sequential, single-electron tunneling mechanism. Next, we chemically fuse two clusters to realize a larger cluster dimer that behaves as a single electronic unit, possessing a smaller reorganization energy and more accessible redox states than the monomeric analogues. As a result, dimer-based devices exhibit significantly higher currents and can even be pushed to current saturation at high bias. Owing to these controllable properties, single-cluster junctions serve as an excellent platform for exploring incoherent charge transport processes at the nanoscale. With this understanding, as well as properties such as nonlinear I-V characteristics and rectification, these molecular clusters may function as conductive inorganic nodes in new devices and materials.
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Affiliation(s)
- Suman Gunasekaran
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Douglas A Reed
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Daniel W Paley
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | | | - Latha Venkataraman
- Department of Chemistry, Columbia University, New York, New York 10027, United States.,Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, United States
| | - Michael L Steigerwald
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Xavier Roy
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Colin Nuckolls
- Department of Chemistry, Columbia University, New York, New York 10027, United States
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49
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Howe L, Castellanos-Beltran MA, Sirois AJ, Olaya D, Biesecker J, Dresselhaus PD, Benz SP, Hopkins PF. Digital Control of a Superconducting Qubit Using a Josephson Pulse Generator at 3 K. PRX QUANTUM : A PHYSICAL REVIEW JOURNAL 2020; 3:10.1103/prxquantum.3.010350. [PMID: 36726390 PMCID: PMC9888300 DOI: 10.1103/prxquantum.3.010350] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Scaling of quantum computers to fault-tolerant levels relies critically on the integration of energy-efficient, stable, and reproducible qubit control and readout electronics. In comparison to traditional semiconductor-control electronics (TSCE) located at room temperature, the signals generated by rf sources based on Josephson-junctions (JJs) benefit from small device sizes, low power dissipation, intrinsic calibration, superior reproducibility, and insensitivity to ambient fluctuations. Previous experiments to colocate qubits and JJ-based control electronics have resulted in quasiparticle poisoning of the qubit, degrading the coherence and lifetime of the qubit. In this paper, we digitally control a 0.01-K transmon qubit with pulses from a Josephson pulse generator (JPG) located at the 3-K stage of a dilution refrigerator. We directly compare the qubit lifetime T 1, the coherence time T 2 * , and the thermal occupation P th when the qubit is controlled by the JPG circuit versus the TSCE setup. We find agreement to within the daily fluctuations of ±0.5 μs and ±2 μs for T 1 and T 2 * , respectively, and agreement to within the 1% error for P th. Additionally, we perform randomized benchmarking to measure an average JPG gate error of 2.1 × 10-2. In combination with a small device size (< 25 mm2) and low on-chip power dissipation (≪100 μW), these results are an important step toward demonstrating the viability of using JJ-based control electronics located at temperature stages higher than the mixing-chamber stage in highly scaled superconducting quantum information systems.
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Affiliation(s)
- L. Howe
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | | | - A. J. Sirois
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - D. Olaya
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
- University of Colorado, Boulder, Colorado 80309, USA
| | - J. Biesecker
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - P. D. Dresselhaus
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - S. P. Benz
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - P. F. Hopkins
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
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