1
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Nigro A, Jutzi E, Oppliger F, De Palma F, Olsen C, Ruiz-Caridad A, Gadea G, Scarlino P, Zardo I, Hofmann A. Demonstration of Microwave Resonators and Double Quantum Dots on Optimized Reverse-Graded Ge/SiGe Heterostructures. ACS APPLIED ELECTRONIC MATERIALS 2024; 6:5094-5100. [PMID: 39070085 PMCID: PMC11270818 DOI: 10.1021/acsaelm.4c00654] [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: 04/14/2024] [Revised: 05/23/2024] [Accepted: 06/12/2024] [Indexed: 07/30/2024]
Abstract
One of the most promising platforms for the realization of spin-based quantum computing are planar germanium quantum wells embedded between silicon-germanium barriers. To achieve comparably thin stacks with little surface roughness, this type of heterostructure can be grown using the so-called reverse linear grading approach, where the growth starts with a virtual germanium substrate followed by a graded silicon-germanium alloy with an increasing silicon content. However, the compatibility of such reverse-graded heterostructures with superconducting microwave resonators has not yet been demonstrated. Here, we report on the successful realization of well-controlled double quantum dots and high-quality coplanar waveguide resonators on the same reverse-graded Ge/SiGe heterostructure.
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Affiliation(s)
- Arianna Nigro
- Physics
Department, University of Basel, Klingelbergstrasse 82, Basel CH-4056, Switzerland
| | - Eric Jutzi
- Physics
Department, University of Basel, Klingelbergstrasse 82, Basel CH-4056, Switzerland
| | - Fabian Oppliger
- Hybrid
Quantum Circuits Laboratory, Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland
| | - Franco De Palma
- Hybrid
Quantum Circuits Laboratory, Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland
| | - Christian Olsen
- Physics
Department, University of Basel, Klingelbergstrasse 82, Basel CH-4056, Switzerland
| | - Alicia Ruiz-Caridad
- Physics
Department, University of Basel, Klingelbergstrasse 82, Basel CH-4056, Switzerland
| | - Gerard Gadea
- Physics
Department, University of Basel, Klingelbergstrasse 82, Basel CH-4056, Switzerland
- Swiss
Nanoscience Institute, Klingelbergstrasse 82, Basel CH-4056, Switzerland
| | - Pasquale Scarlino
- Hybrid
Quantum Circuits Laboratory, Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland
| | - Ilaria Zardo
- Physics
Department, University of Basel, Klingelbergstrasse 82, Basel CH-4056, Switzerland
- Swiss
Nanoscience Institute, Klingelbergstrasse 82, Basel CH-4056, Switzerland
| | - Andrea Hofmann
- Physics
Department, University of Basel, Klingelbergstrasse 82, Basel CH-4056, Switzerland
- Swiss
Nanoscience Institute, Klingelbergstrasse 82, Basel CH-4056, Switzerland
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2
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Ruckriegel MJ, Gächter LM, Kealhofer D, Bahrami Panah M, Tong C, Adam C, Masseroni M, Duprez H, Garreis R, Watanabe K, Taniguchi T, Wallraff A, Ihn T, Ensslin K, Huang WW. Electric Dipole Coupling of a Bilayer Graphene Quantum Dot to a High-Impedance Microwave Resonator. NANO LETTERS 2024; 24:7508-7514. [PMID: 38833415 PMCID: PMC11194813 DOI: 10.1021/acs.nanolett.4c01791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 05/31/2024] [Accepted: 05/31/2024] [Indexed: 06/06/2024]
Abstract
We implement circuit quantum electrodynamics (cQED) with quantum dots in bilayer graphene, a maturing material platform that can host long-lived spin and valley states. Our device combines a high-impedance (Zr ≈ 1 kΩ) superconducting microwave resonator with a double quantum dot electrostatically defined in a graphene-based van der Waals heterostructure. Electric dipole coupling between the subsystems allows the resonator to sense the electric susceptibility of the double quantum dot from which we reconstruct its charge stability diagram. We achieve sensitive and fast detection of the interdot transition with a signal-to-noise ratio of 3.5 within 1 μs integration time. The charge-photon interaction is quantified in the dispersive and resonant regimes by comparing the resonator response to input-output theory, yielding a coupling strength of g/2π = 49.7 MHz. Our results introduce cQED as a probe for quantum dots in van der Waals materials and indicate a path toward coherent charge-photon coupling with bilayer graphene quantum dots.
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Affiliation(s)
- Max J. Ruckriegel
- Laboratory
for Solid State Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Lisa M. Gächter
- Laboratory
for Solid State Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - David Kealhofer
- Laboratory
for Solid State Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Mohsen Bahrami Panah
- Laboratory
for Solid State Physics, ETH Zürich, CH-8093 Zürich, Switzerland
- Quantum
Center, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Chuyao Tong
- Laboratory
for Solid State Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Christoph Adam
- Laboratory
for Solid State Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Michele Masseroni
- Laboratory
for Solid State Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Hadrien Duprez
- Laboratory
for Solid State Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Rebekka Garreis
- Laboratory
for Solid State Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Kenji Watanabe
- Research
Center for Electronic and Optical Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Takashi Taniguchi
- Research
Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Andreas Wallraff
- Laboratory
for Solid State Physics, ETH Zürich, CH-8093 Zürich, Switzerland
- Quantum
Center, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Thomas Ihn
- Laboratory
for Solid State Physics, ETH Zürich, CH-8093 Zürich, Switzerland
- Quantum
Center, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Klaus Ensslin
- Laboratory
for Solid State Physics, ETH Zürich, CH-8093 Zürich, Switzerland
- Quantum
Center, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Wei Wister Huang
- Laboratory
for Solid State Physics, ETH Zürich, CH-8093 Zürich, Switzerland
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3
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de Jong D, Prosko CG, Han L, Malinowski FK, Liu Y, Kouwenhoven LP, Pfaff W. Controllable Single Cooper Pair Splitting in Hybrid Quantum Dot Systems. PHYSICAL REVIEW LETTERS 2023; 131:157001. [PMID: 37897758 DOI: 10.1103/physrevlett.131.157001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 09/07/2023] [Indexed: 10/30/2023]
Abstract
Cooper pair splitters hold utility as a platform for investigating the entanglement of electrons in Cooper pairs, but probing splitters with voltage-biased Ohmic contacts prevents the retention of electrons from split pairs since they can escape to the drain reservoirs. We report the ability to controllably split and retain single Cooper pairs in a multi-quantum-dot device isolated from lead reservoirs, and separately demonstrate a technique for detecting the electrons emerging from a split pair. First, we identify a coherent Cooper pair splitting charge transition using dispersive gate sensing at GHz frequencies. Second, we utilize a double quantum dot as an electron parity sensor to detect parity changes resulting from electrons emerging from a superconducting island.
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Affiliation(s)
- Damaz de Jong
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
| | - Christian G Prosko
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
| | - Lin Han
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
| | - Filip K Malinowski
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
| | - Yu Liu
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Leo P Kouwenhoven
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
| | - Wolfgang Pfaff
- Department of Physics and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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4
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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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5
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Bonsen T, Harvey-Collard P, Russ M, Dijkema J, Sammak A, Scappucci G, Vandersypen LMK. Probing the Jaynes-Cummings Ladder with Spin Circuit Quantum Electrodynamics. PHYSICAL REVIEW LETTERS 2023; 130:137001. [PMID: 37067307 DOI: 10.1103/physrevlett.130.137001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 01/11/2023] [Indexed: 06/19/2023]
Abstract
We report observations of transitions between excited states in the Jaynes-Cummings ladder of circuit quantum electrodynamics with electron spins (spin circuit QED). We show that unexplained features in recent experimental work correspond to such transitions and present an input-output framework that includes these effects. In new experiments, we first reproduce previous observations and then reveal both excited-state transitions and multiphoton transitions by increasing the probe power and using two-tone spectroscopy. This ability to probe the Jaynes-Cummings ladder is enabled by improvements in the coupling-to-decoherence ratio, and shows an increase in the maturity of spin circuit QED as an interesting platform for studying quantum phenomena.
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Affiliation(s)
- Tobias Bonsen
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, Netherlands
| | - Patrick Harvey-Collard
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, Netherlands
| | - Maximilian Russ
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, Netherlands
| | - Jurgen Dijkema
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, Netherlands
| | - Amir Sammak
- QuTech and Netherlands Organization for Applied Scientific Research (TNO), 2628 CJ Delft, Netherlands
| | - Giordano Scappucci
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, Netherlands
| | - Lieven M K Vandersypen
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, Netherlands
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6
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Zwolak JP, Taylor JM. Colloquium: Advances in automation of quantum dot devices control. REVIEWS OF MODERN PHYSICS 2023; 95:10.1103/revmodphys.95.011006. [PMID: 37051403 PMCID: PMC10088060 DOI: 10.1103/revmodphys.95.011006] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Arrays of quantum dots (QDs) are a promising candidate system to realize scalable, coupled qubit systems and serve as a fundamental building block for quantum computers. In such semiconductor quantum systems, devices now have tens of individual electrostatic and dynamical voltages that must be carefully set to localize the system into the single-electron regime and to realize good qubit operational performance. The mapping of requisite QD locations and charges to gate voltages presents a challenging classical control problem. With an increasing number of QD qubits, the relevant parameter space grows sufficiently to make heuristic control unfeasible. In recent years, there has been considerable effort to automate device control that combines script-based algorithms with machine learning (ML) techniques. In this Colloquium, a comprehensive overview of the recent progress in the automation of QD device control is presented, with a particular emphasis on silicon- and GaAs-based QDs formed in two-dimensional electron gases. Combining physics-based modeling with modern numerical optimization and ML has proven effective in yielding efficient, scalable control. Further integration of theoretical, computational, and experimental efforts with computer science and ML holds vast potential in advancing semiconductor and other platforms for quantum computing.
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Affiliation(s)
| | - Jacob M. Taylor
- Joint Quantum Institute, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
- Joint Center for Quantum Information and Computer Science, University of Maryland, College Park, Maryland 20742, USA
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7
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Secchi A, Troiani F. Multi-Dimensional Quantum Capacitance of the Two-Site Hubbard Model: The Role of Tunable Interdot Tunneling. ENTROPY (BASEL, SWITZERLAND) 2022; 25:82. [PMID: 36673222 PMCID: PMC9857432 DOI: 10.3390/e25010082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 12/19/2022] [Accepted: 12/27/2022] [Indexed: 06/17/2023]
Abstract
Few-electron states confined in quantum-dot arrays are key objects in quantum computing. The discrimination between these states is essential for the readout of a (multi-)qubit state, and can be achieved through a measurement of the quantum capacitance within the gate-reflectometry approach. For a system controlled by several gates, the dependence of the measured capacitance on the direction of the oscillations in the voltage space is captured by the quantum capacitance matrix. Herein, we apply this tool to study a double quantum dot coupled to three gates, which enable the tuning of both the bias and the tunneling between the two dots. Analytical solutions for the two-electron case are derived within a Hubbard model, showing the overall dependence of the quantum capacitance matrix on the applied gate voltages. In particular, we investigate the role of the tunneling gate and reveal the possibility of exploiting interdot coherences in addition to charge displacements between the dots. Our results can be directly applied to double-dot experimental setups, and pave the way for further applications to larger arrays of quantum dots.
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8
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Tormo-Queralt R, Møller CB, Czaplewski DA, Gruber G, Cagetti M, Forstner S, Urgell-Ollé N, Sanchez-Naranjo JA, Samanta C, Miller CS, Bachtold A. Novel Nanotube Multiquantum Dot Devices. NANO LETTERS 2022; 22:8541-8549. [PMID: 36287197 PMCID: PMC9650726 DOI: 10.1021/acs.nanolett.2c03034] [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: 08/01/2022] [Revised: 10/20/2022] [Indexed: 06/16/2023]
Abstract
Addressable quantum states well isolated from the environment are of considerable interest for quantum information science and technology. Carbon nanotubes are an appealing system, since a perfect crystal can be grown without any missing atoms and its cylindrical structure prevents ill-defined atomic arrangement at the surface. Here, we develop a reliable process to fabricate compact multielectrode circuits that can sustain the harsh conditions of the nanotube growth. Nanotubes are suspended over multiple gate electrodes, which are themselves structured over narrow dielectric ridges to reduce the effect of the charge fluctuators of the substrate. We measure high-quality double- and triple-quantum dot charge stability diagrams. Transport measurements through the triple-quantum dot indicate long-range tunneling of single electrons between the left and right quantum dots. This work paves the way to the realization of a new generation of condensed-matter devices in an ultraclean environment, including spin qubits, mechanical qubits, and quantum simulators.
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Affiliation(s)
- R. Tormo-Queralt
- ICFO
- Institut De Ciencies Fotoniques, The Barcelona
Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - C. B. Møller
- ICFO
- Institut De Ciencies Fotoniques, The Barcelona
Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - D. A. Czaplewski
- Center
for Nanoscale Materials, Argonne National
Laboratory, Argonne, Illinois 60439, United States
| | - G. Gruber
- ICFO
- Institut De Ciencies Fotoniques, The Barcelona
Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - M. Cagetti
- ICFO
- Institut De Ciencies Fotoniques, The Barcelona
Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - S. Forstner
- ICFO
- Institut De Ciencies Fotoniques, The Barcelona
Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - N. Urgell-Ollé
- ICFO
- Institut De Ciencies Fotoniques, The Barcelona
Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - J. A. Sanchez-Naranjo
- ICFO
- Institut De Ciencies Fotoniques, The Barcelona
Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - C. Samanta
- ICFO
- Institut De Ciencies Fotoniques, The Barcelona
Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - C. S. Miller
- Center
for Nanoscale Materials, Argonne National
Laboratory, Argonne, Illinois 60439, United States
| | - A. Bachtold
- ICFO
- Institut De Ciencies Fotoniques, The Barcelona
Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
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9
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Keith D, Chung Y, Kranz L, Thorgrimsson B, Gorman SK, Simmons MY. Ramped measurement technique for robust high-fidelity spin qubit readout. SCIENCE ADVANCES 2022; 8:eabq0455. [PMID: 36070386 PMCID: PMC9451149 DOI: 10.1126/sciadv.abq0455] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 07/21/2022] [Indexed: 06/15/2023]
Abstract
State preparation and measurement of single-electron spin qubits typically rely on spin-to-charge conversion where a spin-dependent charge transition of the electron is detected by a coupled charge sensor. For high-fidelity, fast readout, this process requires that the qubit energy is much larger than the temperature of the system limiting the temperature range for measurements. Here, we demonstrate an initialization and measurement technique that involves voltage ramps rather than static voltages allowing us to achieve state-to-charge readout fidelities above 99% for qubit energies almost half that required by traditional methods. This previously unidentified measurement technique is highly relevant for achieving high-fidelity electron spin readout at higher temperature operation and offers a number of pragmatic benefits compared to traditional energy-selective readout such as real-time dynamic feedback and minimal alignment procedures.
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10
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Mutter PM, Burkard G. Fingerprints of Qubit Noise in Transient Cavity Transmission. PHYSICAL REVIEW LETTERS 2022; 128:236801. [PMID: 35749203 DOI: 10.1103/physrevlett.128.236801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 05/10/2022] [Indexed: 06/15/2023]
Abstract
Noise affects the coherence of qubits and thereby places a bound on the performance of quantum computers. We theoretically study a generic two-level system with fluctuating control parameters in a photonic cavity and find that basic features of the noise spectral density are imprinted in the transient transmission through the cavity. We obtain analytical expressions for generic noise and proceed to study the cases of quasistatic, white and 1/f^{α} noise in more detail. Additionally, we propose a way of extracting the noise power spectral density in a frequency band only bounded by the range of the qubit-cavity detuning and with an exponentially decaying error due to finite measurement times. Our results suggest that measurements of the time-dependent transmission probability represent a novel way of extracting noise characteristics.
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Affiliation(s)
- Philipp M Mutter
- Department of Physics, University of Konstanz, D-78457 Konstanz, Germany
| | - Guido Burkard
- Department of Physics, University of Konstanz, D-78457 Konstanz, Germany
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11
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Cochrane L, Lundberg T, Ibberson DJ, Ibberson LA, Hutin L, Bertrand B, Stelmashenko N, Robinson JWA, Vinet M, Seshia AA, Gonzalez-Zalba MF. Parametric Amplifiers Based on Quantum Dots. PHYSICAL REVIEW LETTERS 2022; 128:197701. [PMID: 35622052 DOI: 10.1103/physrevlett.128.197701] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 03/30/2022] [Indexed: 06/15/2023]
Abstract
Josephson parametric amplifiers (JPAs) approaching quantum-limited noise performance have been instrumental in enabling high fidelity readout of superconducting qubits and, recently, semiconductor quantum dots (QDs). We propose that the quantum capacitance arising in electronic two-level systems (the dual of Josephson inductance) can provide an alternative dissipationless nonlinear element for parametric amplification. We experimentally demonstrate phase-sensitive parametric amplification using a QD-reservoir electron transition in a CMOS nanowire split-gate transistor embedded in a 1.8 GHz superconducting lumped-element microwave cavity, achieving parametric gains of -3 to +3 dB, limited by Sisyphus dissipation. Using a semiclassical model, we find an optimized design within current technological capabilities could achieve gains and bandwidths comparable to JPAs, while providing complementary specifications with respect to integration in semiconductor platforms or operation at higher magnetic fields.
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Affiliation(s)
- Laurence Cochrane
- Nanoscience Centre, Department of Engineering, University of Cambridge, Cambridge CB3 0FF, United Kingdom
- Quantum Motion Technologies, Windsor House, Cornwall Road, Harrogate HG1 2PW, United Kingdom
| | - Theodor Lundberg
- Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
- Hitachi Cambridge Laboratory, J.J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - David J Ibberson
- Quantum Motion Technologies, Windsor House, Cornwall Road, Harrogate HG1 2PW, United Kingdom
| | - Lisa A Ibberson
- Hitachi Cambridge Laboratory, J.J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Louis Hutin
- CEA/LETI-MINATEC, CEA-Grenoble, 38000 Grenoble, France
| | | | - Nadia Stelmashenko
- Department of Materials Science & Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, United Kingdom
| | - Jason W A Robinson
- Department of Materials Science & Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, United Kingdom
| | - Maud Vinet
- CEA/LETI-MINATEC, CEA-Grenoble, 38000 Grenoble, France
| | - Ashwin A Seshia
- Nanoscience Centre, Department of Engineering, University of Cambridge, Cambridge CB3 0FF, United Kingdom
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12
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Xue X, Russ M, Samkharadze N, Undseth B, Sammak A, Scappucci G, Vandersypen LMK. Quantum logic with spin qubits crossing the surface code threshold. Nature 2022; 601:343-347. [PMID: 35046604 PMCID: PMC8770146 DOI: 10.1038/s41586-021-04273-w] [Citation(s) in RCA: 55] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 11/22/2021] [Indexed: 11/12/2022]
Abstract
High-fidelity control of quantum bits is paramount for the reliable execution of quantum algorithms and for achieving fault tolerance-the ability to correct errors faster than they occur1. The central requirement for fault tolerance is expressed in terms of an error threshold. Whereas the actual threshold depends on many details, a common target is the approximately 1% error threshold of the well-known surface code2,3. Reaching two-qubit gate fidelities above 99% has been a long-standing major goal for semiconductor spin qubits. These qubits are promising for scaling, as they can leverage advanced semiconductor technology4. Here we report a spin-based quantum processor in silicon with single-qubit and two-qubit gate fidelities, all of which are above 99.5%, extracted from gate-set tomography. The average single-qubit gate fidelities remain above 99% when including crosstalk and idling errors on the neighbouring qubit. Using this high-fidelity gate set, we execute the demanding task of calculating molecular ground-state energies using a variational quantum eigensolver algorithm5. Having surpassed the 99% barrier for the two-qubit gate fidelity, semiconductor qubits are well positioned on the path to fault tolerance and to possible applications in the era of noisy intermediate-scale quantum devices.
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Affiliation(s)
- Xiao Xue
- QuTech, Delft University of Technology, Delft, The Netherlands
- Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Maximilian Russ
- QuTech, Delft University of Technology, Delft, The Netherlands
- Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Nodar Samkharadze
- QuTech, Delft University of Technology, Delft, The Netherlands
- Netherlands Organisation for Applied Scientific Research (TNO), Delft, The Netherlands
| | - Brennan Undseth
- QuTech, Delft University of Technology, Delft, The Netherlands
- Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - 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
| | - Lieven M K Vandersypen
- QuTech, Delft University of Technology, Delft, The Netherlands.
- Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands.
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13
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Tadokoro M, Nakajima T, Kobayashi T, Takeda K, Noiri A, Tomari K, Yoneda J, Tarucha S, Kodera T. Designs for a two-dimensional Si quantum dot array with spin qubit addressability. Sci Rep 2021; 11:19406. [PMID: 34593827 PMCID: PMC8484262 DOI: 10.1038/s41598-021-98212-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Accepted: 09/03/2021] [Indexed: 11/16/2022] Open
Abstract
Electron spins in Si are an attractive platform for quantum computation, backed with their scalability and fast, high-fidelity quantum logic gates. Despite the importance of two-dimensional integration with efficient connectivity between qubits for medium- to large-scale quantum computation, however, a practical device design that guarantees qubit addressability is yet to be seen. Here, we propose a practical 3 × 3 quantum dot device design and a larger-scale design as a longer-term target. The design goal is to realize qubit connectivity to the four nearest neighbors while ensuring addressability. We show that a 3 × 3 quantum dot array can execute four-qubit Grover’s algorithm more efficiently than the one-dimensional counterpart. To scale up the two-dimensional array beyond 3 × 3, we propose a novel structure with ferromagnetic gate electrodes. Our results showcase the possibility of medium-sized quantum processors in Si with fast quantum logic gates and long coherence times.
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Affiliation(s)
- Masahiro Tadokoro
- Department of Electrical and Electronic Engineering, Tokyo Institute of Technology, Meguro-ku, Tokyo, 152-8552, Japan.,Center for Emergent Matter Science, RIKEN, Wako-shi, Saitama, 351-0198, Japan
| | - Takashi Nakajima
- Center for Emergent Matter Science, RIKEN, Wako-shi, Saitama, 351-0198, Japan
| | - Takashi Kobayashi
- RIKEN Center for Quantum Computing, RIKEN, Wako-shi, Saitama, 351-0198, Japan
| | - Kenta Takeda
- Center for Emergent Matter Science, RIKEN, Wako-shi, Saitama, 351-0198, Japan
| | - Akito Noiri
- Center for Emergent Matter Science, RIKEN, Wako-shi, Saitama, 351-0198, Japan
| | - Kaito Tomari
- Department of Electrical and Electronic Engineering, Tokyo Institute of Technology, Meguro-ku, Tokyo, 152-8552, Japan
| | - Jun Yoneda
- Tokyo Tech Academy for Super Smart Society, Tokyo Institute of Technology, Meguro-ku, Tokyo, 152-8552, Japan
| | - Seigo Tarucha
- Center for Emergent Matter Science, RIKEN, Wako-shi, Saitama, 351-0198, Japan.,RIKEN Center for Quantum Computing, RIKEN, Wako-shi, Saitama, 351-0198, Japan
| | - Tetsuo Kodera
- Department of Electrical and Electronic Engineering, Tokyo Institute of Technology, Meguro-ku, Tokyo, 152-8552, Japan.
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14
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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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15
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Hendrickx NW, Lawrie WIL, Petit L, Sammak A, Scappucci G, Veldhorst M. A single-hole spin qubit. Nat Commun 2020; 11:3478. [PMID: 32651363 PMCID: PMC7351715 DOI: 10.1038/s41467-020-17211-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 06/16/2020] [Indexed: 11/09/2022] Open
Abstract
Qubits based on quantum dots have excellent prospects for scalable quantum technology due to their compatibility with standard semiconductor manufacturing. While early research focused on the simpler electron system, recent demonstrations using multi-hole quantum dots illustrated the favourable properties holes can offer for fast and scalable quantum control. Here, we establish a single-hole spin qubit in germanium and demonstrate the integration of single-shot readout and quantum control. We deplete a planar germanium double quantum dot to the last hole, confirmed by radio-frequency reflectrometry charge sensing. To demonstrate the integration of single-shot readout and qubit operation, we show Rabi driving on both qubits. We find remarkable electric control over the qubit resonance frequencies, providing great qubit addressability. Finally, we analyse the spin relaxation time, which we find to exceed one millisecond, setting the benchmark for hole quantum dot qubits. The ability to coherently manipulate a single hole spin underpins the quality of strained germanium and defines an excellent starting point for the construction of quantum hardware. While most results so far in semiconductor spin-based quantum computation use electron spins, devices based on hole spins may have more favourable properties for quantum applications. Here, the authors demonstrate single-shot readout and coherent control of a qubit made from a single hole spin.
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Affiliation(s)
- N W Hendrickx
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, P. O. Box 5046, 2600 GA, Delft, The Netherlands.
| | - W I L Lawrie
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, P. O. Box 5046, 2600 GA, Delft, The Netherlands
| | - L Petit
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, P. O. Box 5046, 2600 GA, Delft, The Netherlands
| | - A Sammak
- QuTech and Netherlands Organisation for Applied Scientific Research (TNO), Stieltjesweg 1, 2628 CK, Delft, The Netherlands
| | - G Scappucci
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, P. O. Box 5046, 2600 GA, Delft, The Netherlands
| | - M Veldhorst
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, P. O. Box 5046, 2600 GA, Delft, The Netherlands.
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16
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Abstract
Among the different platforms for quantum information processing, individual electron spins in semiconductor quantum dots stand out for their long coherence times and potential for scalable fabrication. The past years have witnessed substantial progress in the capabilities of spin qubits. However, coupling between distant electron spins, which is required for quantum error correction, presents a challenge, and this goal remains the focus of intense research. Quantum teleportation is a canonical method to transmit qubit states, but it has not been implemented in quantum-dot spin qubits. Here, we present evidence for quantum teleportation of electron spin qubits in semiconductor quantum dots. Although we have not performed quantum state tomography to definitively assess the teleportation fidelity, our data are consistent with conditional teleportation of spin eigenstates, entanglement swapping, and gate teleportation. Such evidence for all-matter spin-state teleportation underscores the capabilities of exchange-coupled spin qubits for quantum-information transfer. Despite recent demonstrations of coherent spin-state transfer in arrays of spin qubits via exchange interaction, all-matter spin-state teleportation is still out of reach. Here the authors provide evidence for conditional teleportation of quantum-dot spin states, entanglement swapping, and gate teleportation.
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17
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Schaal S, Ahmed I, Haigh JA, Hutin L, Bertrand B, Barraud S, Vinet M, Lee CM, Stelmashenko N, Robinson JWA, Qiu JY, Hacohen-Gourgy S, Siddiqi I, Gonzalez-Zalba MF, Morton JJL. Fast Gate-Based Readout of Silicon Quantum Dots Using Josephson Parametric Amplification. PHYSICAL REVIEW LETTERS 2020; 124:067701. [PMID: 32109120 DOI: 10.1103/physrevlett.124.067701] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 01/17/2020] [Indexed: 06/10/2023]
Abstract
Spins in silicon quantum devices are promising candidates for large-scale quantum computing. Gate-based sensing of spin qubits offers a compact and scalable readout with high fidelity, however, further improvements in sensitivity are required to meet the fidelity thresholds and measurement timescales needed for the implementation of fast feedback in error correction protocols. Here, we combine radio-frequency gate-based sensing at 622 MHz with a Josephson parametric amplifier, that operates in the 500-800 MHz band, to reduce the integration time required to read the state of a silicon double quantum dot formed in a nanowire transistor. Based on our achieved signal-to-noise ratio, we estimate that singlet-triplet single-shot readout with an average fidelity of 99.7% could be performed in 1 μs, well below the requirements for fault-tolerant readout and 30 times faster than without the Josephson parametric amplifier. Additionally, the Josephson parametric amplifier allows operation at a lower radio-frequency power while maintaining identical signal-to-noise ratio. We determine a noise temperature of 200 mK with a contribution from the Josephson parametric amplifier (25%), cryogenic amplifier (25%) and the resonator (50%), showing routes to further increase the readout speed.
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Affiliation(s)
- S Schaal
- London Centre for Nanotechnology, University College London, London WC1H 0AH, United Kingdom
| | - I Ahmed
- Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - J A Haigh
- Hitachi Cambridge Laboratory, J.J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - L Hutin
- CEA, LETI, Minatec Campus, F-38054 Grenoble, France
| | - B Bertrand
- CEA, LETI, Minatec Campus, F-38054 Grenoble, France
| | - S Barraud
- CEA, LETI, Minatec Campus, F-38054 Grenoble, France
| | - M Vinet
- CEA, LETI, Minatec Campus, F-38054 Grenoble, France
| | - C-M Lee
- Department of Materials Science & Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, United Kingdom
| | - N Stelmashenko
- Department of Materials Science & Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, United Kingdom
| | - J W A Robinson
- Department of Materials Science & Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, United Kingdom
| | - J Y Qiu
- Quantum Nanoelectronics Laboratory, Department of Physics, University of California, Berkeley California 94720, USA
| | - S Hacohen-Gourgy
- Quantum Nanoelectronics Laboratory, Department of Physics, University of California, Berkeley California 94720, USA
| | - I Siddiqi
- Quantum Nanoelectronics Laboratory, Department of Physics, University of California, Berkeley California 94720, USA
| | - M F Gonzalez-Zalba
- Hitachi Cambridge Laboratory, J.J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - J J L Morton
- London Centre for Nanotechnology, University College London, London WC1H 0AH, United Kingdom
- Department of Electronic & Electrical Engineering, University College London, London WC1E 7JE, United Kingdom
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18
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Noiri A, Takeda K, Yoneda J, Nakajima T, Kodera T, Tarucha S. Radio-Frequency-Detected Fast Charge Sensing in Undoped Silicon Quantum Dots. NANO LETTERS 2020; 20:947-952. [PMID: 31944116 DOI: 10.1021/acs.nanolett.9b03847] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Spin qubits in silicon quantum dots offer a promising platform for a quantum computer as they have a long coherence time and scalability. The charge sensing technique plays an essential role in reading out the spin qubit as well as tuning the device parameters, and therefore, its performance in terms of measurement bandwidth and sensitivity is an important factor in spin qubit experiments. Here we demonstrate fast and sensitive charge sensing by radio frequency reflectometry of an undoped, accumulation-mode Si/SiGe double quantum dot. We show that the large parasitic capacitance in typical accumulation-mode gate geometries impedes reflectometry measurements. We present a gate geometry that significantly reduces the parasitic capacitance and enables fast single-shot readout. The technique allows us to distinguish between the singly- and doubly occupied two-electron states under the Pauli spin blockade condition in an integration time of 0.8 μs, the shortest value ever reported in silicon, by the signal-to-noise ratio of 6. These results provide a guideline for designing silicon spin qubit devices suitable for the fast and high-fidelity readout.
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Affiliation(s)
- Akito Noiri
- RIKEN , Center for Emergent Matter Science (CEMS) , Wako-shi , Saitama 351-0198 , Japan
| | - Kenta Takeda
- RIKEN , Center for Emergent Matter Science (CEMS) , Wako-shi , Saitama 351-0198 , Japan
| | - Jun Yoneda
- RIKEN , Center for Emergent Matter Science (CEMS) , Wako-shi , Saitama 351-0198 , Japan
| | - Takashi Nakajima
- RIKEN , Center for Emergent Matter Science (CEMS) , Wako-shi , Saitama 351-0198 , Japan
| | - Tetsuo Kodera
- Department of Electrical and Electronic Engineering , Tokyo Institute of Technology , O-okayama , Meguro-ku, Tokyo 152-8552 , Japan
| | - Seigo Tarucha
- RIKEN , Center for Emergent Matter Science (CEMS) , Wako-shi , Saitama 351-0198 , Japan
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19
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Zhao R, Tanttu T, Tan KY, Hensen B, Chan KW, Hwang JCC, Leon RCC, Yang CH, Gilbert W, Hudson FE, Itoh KM, Kiselev AA, Ladd TD, Morello A, Laucht A, Dzurak AS. Single-spin qubits in isotopically enriched silicon at low magnetic field. Nat Commun 2019; 10:5500. [PMID: 31796728 PMCID: PMC6890755 DOI: 10.1038/s41467-019-13416-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 11/06/2019] [Indexed: 11/09/2022] Open
Abstract
Single-electron spin qubits employ magnetic fields on the order of 1 Tesla or above to enable quantum state readout via spin-dependent-tunnelling. This requires demanding microwave engineering for coherent spin resonance control, which limits the prospects for large scale multi-qubit systems. Alternatively, singlet-triplet readout enables high-fidelity spin-state measurements in much lower magnetic fields, without the need for reservoirs. Here, we demonstrate low-field operation of metal-oxide-silicon quantum dot qubits by combining coherent single-spin control with high-fidelity, single-shot, Pauli-spin-blockade-based ST readout. We discover that the qubits decohere faster at low magnetic fields with [Formula: see text] μs and [Formula: see text] μs at 150 mT. Their coherence is limited by spin flips of residual 29Si nuclei in the isotopically enriched 28Si host material, which occur more frequently at lower fields. Our finding indicates that new trade-offs will be required to ensure the frequency stabilization of spin qubits, and highlights the importance of isotopic enrichment of device substrates for the realization of a scalable silicon-based quantum processor.
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Affiliation(s)
- R Zhao
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, NSW, 2052, Australia.
- National Institute of Standards and Technology, 325 Broadway, Boulder, CO, 80305, USA.
| | - T Tanttu
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, NSW, 2052, Australia
| | - K Y Tan
- QCD Labs, QTF Centre of Excellence, Department of Applied Physics, Aalto University, 00076, Aalto, Finland
- IQM Finland Oy, Vaisalantie 6 C, 02130, Espoo, Finland
| | - B Hensen
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, NSW, 2052, Australia
| | - K W Chan
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, NSW, 2052, Australia
| | - J C C Hwang
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, NSW, 2052, Australia
- Research and Prototype Foundry, The University of Sydney, Sydney, NSW, 2006, Australia
| | - R C C Leon
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, NSW, 2052, Australia
| | - C H Yang
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, NSW, 2052, Australia
| | - W Gilbert
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, NSW, 2052, Australia
| | - F E Hudson
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, NSW, 2052, Australia
| | - K M Itoh
- School of Fundamental Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, 223-8522, Japan
| | - A A Kiselev
- HRL Laboratories, LLC, 3011 Malibu Canyon Road, Malibu, CA, 90265, USA
| | - T D Ladd
- HRL Laboratories, LLC, 3011 Malibu Canyon Road, Malibu, CA, 90265, USA
| | - A Morello
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, NSW, 2052, Australia
| | - A Laucht
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, NSW, 2052, Australia
| | - A S Dzurak
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, NSW, 2052, Australia.
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20
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Volk C, Chatterjee A, Ansaloni F, Marcus CM, Kuemmeth F. Fast Charge Sensing of Si/SiGe Quantum Dots via a High-Frequency Accumulation Gate. NANO LETTERS 2019; 19:5628-5633. [PMID: 31339321 DOI: 10.1021/acs.nanolett.9b02149] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Quantum dot arrays are a versatile platform for the implementation of spin qubits, as high-bandwidth sensor dots can be integrated with single-, double-, and triple-dot qubits yielding fast and high-fidelity qubit readout. However, for undoped silicon devices, reflectometry off sensor ohmics suffers from the finite resistivity of the two-dimensional electron gas (2DEG), and alternative readout methods are limited to measuring qubit capacitance, rather than qubit charge. By coupling a surface-mount resonant circuit to the plunger gate of a high-impedance sensor, we realized a fast charge sensing technique that is compatible with resistive 2DEGs. We demonstrate this by acquiring at high speed charge stability diagrams of double- and triple-dot arrays in Si/SiGe heterostructures as well as pulsed-gate single-shot charge and spin readout with integration times as low as 2.4 μs.
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Affiliation(s)
- Christian Volk
- Center for Quantum Devices, Niels Bohr Institute , University of Copenhagen and Microsoft Quantum Lab Copenhagen , Universitetsparken 5 , 2100 Copenhagen , Denmark
| | - Anasua Chatterjee
- Center for Quantum Devices, Niels Bohr Institute , University of Copenhagen and Microsoft Quantum Lab Copenhagen , Universitetsparken 5 , 2100 Copenhagen , Denmark
| | - Fabio Ansaloni
- Center for Quantum Devices, Niels Bohr Institute , University of Copenhagen and Microsoft Quantum Lab Copenhagen , Universitetsparken 5 , 2100 Copenhagen , Denmark
| | - Charles M Marcus
- Center for Quantum Devices, Niels Bohr Institute , University of Copenhagen and Microsoft Quantum Lab Copenhagen , Universitetsparken 5 , 2100 Copenhagen , Denmark
| | - Ferdinand Kuemmeth
- Center for Quantum Devices, Niels Bohr Institute , University of Copenhagen and Microsoft Quantum Lab Copenhagen , Universitetsparken 5 , 2100 Copenhagen , Denmark
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21
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Hu X. Fast and space-efficient spin sensing. NATURE NANOTECHNOLOGY 2019; 14:735-736. [PMID: 31316155 DOI: 10.1038/s41565-019-0516-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Affiliation(s)
- Xuedong Hu
- Department of Physics, University at Buffalo, SUNY, Buffalo, NY, USA.
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