1
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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2
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Adambukulam C, Johnson BC, Morello A, Laucht A. Hyperfine Spectroscopy and Fast, All-Optical Arbitrary State Initialization and Readout of a Single, Ten-Level ^{73}Ge Vacancy Nuclear Spin Qudit in Diamond. Phys Rev Lett 2024; 132:060603. [PMID: 38394595 DOI: 10.1103/physrevlett.132.060603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 01/11/2024] [Indexed: 02/25/2024]
Abstract
A high-spin nucleus coupled to a color center can act as a long-lived memory qudit in a spin-photon interface. The germanium vacancy (GeV) in diamond has attracted recent attention due to its excellent spectral properties and provides access to the ten-dimensional Hilbert space of the I=9/2 ^{73}Ge nucleus. Here, we observe the ^{73}GeV hyperfine structure, perform nuclear spin readout, and optically initialize the ^{73}Ge spin into any eigenstate on a μs timescale and with a fidelity of up to ∼84%. Our results establish ^{73}GeV as an optically addressable high-spin quantum platform for a high-efficiency spin-photon interface as well as for foundational quantum physics and metrology.
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Affiliation(s)
- C Adambukulam
- School of Electrical Engineering and Telecommunications, University of New South Wales, Kensington, NSW 2052, Australia
| | - B C Johnson
- School of Science, RMIT University, Melbourne, VIC 3001, Australia
| | - A Morello
- School of Electrical Engineering and Telecommunications, University of New South Wales, Kensington, NSW 2052, Australia
| | - A Laucht
- School of Electrical Engineering and Telecommunications, University of New South Wales, Kensington, NSW 2052, Australia
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3
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Wang Z, Feng M, Serrano S, Gilbert W, Leon RCC, Tanttu T, Mai P, Liang D, Huang JY, Su Y, Lim WH, Hudson FE, Escott CC, Morello A, Yang CH, Dzurak AS, Saraiva A, Laucht A. Jellybean Quantum Dots in Silicon for Qubit Coupling and On-Chip Quantum Chemistry. Adv Mater 2023; 35:e2208557. [PMID: 36805699 DOI: 10.1002/adma.202208557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Revised: 01/13/2023] [Indexed: 05/12/2023]
Abstract
The small size and excellent integrability of silicon metal-oxide-semiconductor (SiMOS) quantum dot spin qubits make them an attractive system for mass-manufacturable, scaled-up quantum processors. Furthermore, classical control electronics can be integrated on-chip, in-between the qubits, if an architecture with sparse arrays of qubits is chosen. In such an architecture qubits are either transported across the chip via shuttling or coupled via mediating quantum systems over short-to-intermediate distances. This paper investigates the charge and spin characteristics of an elongated quantum dot-a so-called jellybean quantum dot-for the prospects of acting as a qubit-qubit coupler. Charge transport, charge sensing, and magneto-spectroscopy measurements are performed on a SiMOS quantum dot device at mK temperature and compared to Hartree-Fock multi-electron simulations. At low electron occupancies where disorder effects and strong electron-electron interaction dominate over the electrostatic confinement potential, the data reveals the formation of three coupled dots, akin to a tunable, artificial molecule. One dot is formed centrally under the gate and two are formed at the edges. At high electron occupancies, these dots merge into one large dot with well-defined spin states, verifying that jellybean dots have the potential to be used as qubit couplers in future quantum computing architectures.
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Affiliation(s)
- Zeheng Wang
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - MengKe Feng
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Santiago Serrano
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - William Gilbert
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
- Diraq, Sydney, NSW, 2052, Australia
| | - Ross C C Leon
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Tuomo Tanttu
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
- Diraq, Sydney, NSW, 2052, Australia
| | - Philip Mai
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Dylan Liang
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Jonathan Y Huang
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Yue Su
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Wee Han Lim
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
- Diraq, Sydney, NSW, 2052, Australia
| | - Fay E Hudson
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
- Diraq, Sydney, NSW, 2052, Australia
| | - Christopher C Escott
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
- Diraq, Sydney, NSW, 2052, Australia
| | - Andrea Morello
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Chih Hwan Yang
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
- Diraq, Sydney, NSW, 2052, Australia
| | - Andrew S Dzurak
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
- Diraq, Sydney, NSW, 2052, Australia
| | - Andre Saraiva
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
- Diraq, Sydney, NSW, 2052, Australia
| | - Arne Laucht
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
- Diraq, Sydney, NSW, 2052, Australia
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4
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Gilbert W, Tanttu T, Lim WH, Feng M, Huang JY, Cifuentes JD, Serrano S, Mai PY, Leon RCC, Escott CC, Itoh KM, Abrosimov NV, Pohl HJ, Thewalt MLW, Hudson FE, Morello A, Laucht A, Yang CH, Saraiva A, Dzurak AS. On-demand electrical control of spin qubits. Nat Nanotechnol 2023; 18:131-136. [PMID: 36635331 DOI: 10.1038/s41565-022-01280-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Accepted: 10/24/2022] [Indexed: 06/17/2023]
Abstract
Once called a 'classically non-describable two-valuedness' by Pauli, the electron spin forms a qubit that is naturally robust to electric fluctuations. Paradoxically, a common control strategy is the integration of micromagnets to enhance the coupling between spins and electric fields, which, in turn, hampers noise immunity and adds architectural complexity. Here we exploit a switchable interaction between spins and orbital motion of electrons in silicon quantum dots, without a micromagnet. The weak effects of relativistic spin-orbit interaction in silicon are enhanced, leading to a speed up in Rabi frequency by a factor of up to 650 by controlling the energy quantization of electrons in the nanostructure. Fast electrical control is demonstrated in multiple devices and electronic configurations. Using the electrical drive, we achieve a coherence time T2,Hahn ≈ 50 μs, fast single-qubit gates with Tπ/2 = 3 ns and gate fidelities of 99.93%, probed by randomized benchmarking. High-performance all-electrical control improves the prospects for scalable silicon quantum computing.
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Affiliation(s)
- Will Gilbert
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia.
- Diraq, Sydney, New South Wales, Australia.
| | - Tuomo Tanttu
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
- Diraq, Sydney, New South Wales, Australia
| | - Wee Han Lim
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
- Diraq, Sydney, New South Wales, Australia
| | - MengKe Feng
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
| | - Jonathan Y Huang
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
| | - Jesus D Cifuentes
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
| | - Santiago Serrano
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
| | - Philip Y Mai
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
| | - Ross C C Leon
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
| | - Christopher C Escott
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
- Diraq, Sydney, New South Wales, Australia
| | - Kohei M Itoh
- School of Fundamental Science and Technology, Keio University, Yokohama, Japan
| | | | | | - Michael L W Thewalt
- Department of Physics, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Fay E Hudson
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
- Diraq, Sydney, New South Wales, Australia
| | - Andrea Morello
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
| | - Arne Laucht
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
- Diraq, Sydney, New South Wales, Australia
| | - Chih Hwan Yang
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
- Diraq, Sydney, New South Wales, Australia
| | - Andre Saraiva
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia.
- Diraq, Sydney, New South Wales, Australia.
| | - Andrew S Dzurak
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia.
- Diraq, Sydney, New South Wales, Australia.
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5
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Zeng HZ, Ngyuen MAP, Ai X, Bennet A, Solntsev AS, Laucht A, Al-Juboori A, Toth M, Mildren RP, Malaney R, Aharonovich I. Integrated room temperature single-photon source for quantum key distribution: publisher's note. Opt Lett 2022; 47:2161. [PMID: 35486749 DOI: 10.1364/ol.460614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Indexed: 06/14/2023]
Abstract
This publisher's note contains a correction to Opt. Lett.47, 1673 (2022)10.1364/OL.454450.
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6
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Zeng HZJ, Ngyuen MAP, Ai X, Bennet A, Solnstev AS, Laucht A, Al-Juboori A, Toth M, Mildren RP, Malaney R, Aharonovich I. Integrated room temperature single-photon source for quantum key distribution. Opt Lett 2022; 47:1673-1676. [PMID: 35363706 DOI: 10.1364/ol.454450] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 02/21/2022] [Indexed: 06/14/2023]
Abstract
High-purity single-photon sources (SPS) that can operate at room temperature are highly desirable for a myriad of applications, including quantum photonics and quantum key distribution. In this work, we realize an ultra-bright solid-state SPS based on an atomic defect in hexagonal boron nitride (hBN) integrated with a solid immersion lens (SIL). The SIL increases the source efficiency by a factor of six, and the integrated system is capable of producing over ten million single photons per second at room temperature. Our results are promising for practical applications of SPS in quantum communication protocols.
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7
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Heinrich AJ, Oliver WD, Vandersypen LMK, Ardavan A, Sessoli R, Loss D, Jayich AB, Fernandez-Rossier J, Laucht A, Morello A. Quantum-coherent nanoscience. Nat Nanotechnol 2021; 16:1318-1329. [PMID: 34845333 DOI: 10.1038/s41565-021-00994-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 09/01/2021] [Indexed: 05/25/2023]
Abstract
For the past three decades nanoscience has widely affected many areas in physics, chemistry and engineering, and has led to numerous fundamental discoveries, as well as applications and products. Concurrently, quantum science and technology has developed into a cross-disciplinary research endeavour connecting these same areas and holds burgeoning commercial promise. Although quantum physics dictates the behaviour of nanoscale objects, quantum coherence, which is central to quantum information, communication and sensing, has not played an explicit role in much of nanoscience. This Review describes fundamental principles and practical applications of quantum coherence in nanoscale systems, a research area we call quantum-coherent nanoscience. We structure this Review according to specific degrees of freedom that can be quantum-coherently controlled in a given nanoscale system, such as charge, spin, mechanical motion and photons. We review the current state of the art and focus on outstanding challenges and opportunities unlocked by the merging of nanoscience and coherent quantum operations.
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Affiliation(s)
- Andreas J Heinrich
- Center for Quantum Nanoscience (QNS), Institute for Basic Science, Seoul, Korea.
- Physics Department, Ewha Womans University, Seoul, Korea.
| | - William D Oliver
- Department of Electrical Engineering and Computer Science, and Department of Physics, MIT, Cambridge, MA, USA
- Lincoln Laboratory, MIT, Lexington, MA, USA
| | | | - Arzhang Ardavan
- CAESR, The Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, UK
| | - Roberta Sessoli
- Department of Chemistry 'U. Schiff' & INSTM, University of Florence, Sesto Fiorentino, Italy
| | - Daniel Loss
- Department of Physics, University of Basel, Basel, Switzerland
| | | | - Joaquin Fernandez-Rossier
- QuantaLab, International Iberian Nanotechnology Laboratory (INL), Braga, Portugal
- Departamento de Física Aplicada, Universidad de Alicante, Alicante, Spain
| | - Arne Laucht
- School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, New South Wales, Australia
| | - Andrea Morello
- School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, New South Wales, Australia.
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8
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Adambukulam C, Sewani VK, Stemp HG, Asaad S, Mądzik MT, Morello A, Laucht A. An ultra-stable 1.5 T permanent magnet assembly for qubit experiments at cryogenic temperatures. Rev Sci Instrum 2021; 92:085106. [PMID: 34470423 DOI: 10.1063/5.0055318] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 07/14/2021] [Indexed: 06/13/2023]
Abstract
Magnetic fields are a standard tool in the toolbox of every physicist and are required for the characterization of materials, as well as the polarization of spins in nuclear magnetic resonance or electron paramagnetic resonance experiments. Quite often, a static magnetic field of sufficiently large, but fixed, magnitude is suitable for these tasks. Here, we present a permanent magnet assembly that can achieve magnetic field strengths of up to 1.5 T over an air gap length of 7 mm. The assembly is based on a Halbach array of neodymium magnets, with the inclusion of the soft magnetic material Supermendur to boost the magnetic field strength inside the air gap. We present the design, simulation, and characterization of the permanent magnet assembly, measuring an outstanding magnetic field stability with a drift rate of |D| < 2.8 ppb/h. Our measurements demonstrate that this assembly can be used for spin qubit experiments inside a dilution refrigerator, successfully replacing the more expensive and bulky superconducting solenoids.
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Affiliation(s)
- C Adambukulam
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, New South Wales 2052, Australia
| | - V K Sewani
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, New South Wales 2052, Australia
| | - H G Stemp
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, New South Wales 2052, Australia
| | - S Asaad
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, New South Wales 2052, Australia
| | - M T Mądzik
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, New South Wales 2052, Australia
| | - A Morello
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, New South Wales 2052, Australia
| | - A Laucht
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, New South Wales 2052, Australia
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9
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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. Sci Adv 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] [What about the content of this article? (0)] [Affiliation(s)] [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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10
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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 Lett 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] [What about the content of this article? (0)] [Affiliation(s)] [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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11
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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: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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12
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Laucht A, Hohls F, Ubbelohde N, Fernando Gonzalez-Zalba M, Reilly DJ, Stobbe S, Schröder T, Scarlino P, Koski JV, Dzurak A, Yang CH, Yoneda J, Kuemmeth F, Bluhm H, Pla J, Hill C, Salfi J, Oiwa A, Muhonen JT, Verhagen E, LaHaye MD, Kim HH, Tsen AW, Culcer D, Geresdi A, Mol JA, Mohan V, Jain PK, Baugh J. Roadmap on quantum nanotechnologies. Nanotechnology 2021; 32:162003. [PMID: 33543734 DOI: 10.1088/1361-6528/abb333] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Quantum phenomena are typically observable at length and time scales smaller than those of our everyday experience, often involving individual particles or excitations. The past few decades have seen a revolution in the ability to structure matter at the nanoscale, and experiments at the single particle level have become commonplace. This has opened wide new avenues for exploring and harnessing quantum mechanical effects in condensed matter. These quantum phenomena, in turn, have the potential to revolutionize the way we communicate, compute and probe the nanoscale world. Here, we review developments in key areas of quantum research in light of the nanotechnologies that enable them, with a view to what the future holds. Materials and devices with nanoscale features are used for quantum metrology and sensing, as building blocks for quantum computing, and as sources and detectors for quantum communication. They enable explorations of quantum behaviour and unconventional states in nano- and opto-mechanical systems, low-dimensional systems, molecular devices, nano-plasmonics, quantum electrodynamics, scanning tunnelling microscopy, and more. This rapidly expanding intersection of nanotechnology and quantum science/technology is mutually beneficial to both fields, laying claim to some of the most exciting scientific leaps of the last decade, with more on the horizon.
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Affiliation(s)
- Arne Laucht
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, New South Wales 2052, Australia
- Author to whom any correspondence should be addressed
| | - Frank Hohls
- Physikalisch-Technische Bundesanstalt, 38116, Braunschweig, Germany
| | - Niels Ubbelohde
- Physikalisch-Technische Bundesanstalt, 38116, Braunschweig, Germany
| | - M Fernando Gonzalez-Zalba
- Quantum Motion Technologies, Nexus, Discovery Way, Leeds, LS2 3AA, United Kingdom
- Present address: Quantum Motion Technologies, Windsor House, Cornwall Road, Harrogate HG1 2PW, United Kingdom
| | - David J Reilly
- School of Physics, University of Sydney, Sydney, NSW 2006, Australia
- Microsoft Corporation, Station Q Sydney, University of Sydney, Sydney, NSW 2006, Australia
| | - Søren Stobbe
- Department of Photonics Engineering, DTU Fotonik, Technical University of Denmark, Building 343, DK-2800 Kgs. Lyngby, Denmark
| | - Tim Schröder
- Department of Physics, Humboldt-Universität zu Berlin, 12489, Berlin, Germany
- Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, 12489 Berlin, Germany
| | | | - Jonne V Koski
- Department of Physics, ETH Zürich, CH-8093, Zürich, Switzerland
| | - Andrew Dzurak
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, New South Wales 2052, Australia
| | - Chih-Hwan Yang
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, New South Wales 2052, Australia
| | - Jun Yoneda
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, New South Wales 2052, Australia
| | - Ferdinand Kuemmeth
- Niels Bohr Institute, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Hendrik Bluhm
- JARA-FIT Institute for Quantum Information, RWTH Aachen University and Forschungszentrum Jülich, 52074, Aachen, Germany
| | - Jarryd Pla
- School of Electrical Engineering and Telecommunications, UNSW Sydney, New South Wales 2052, Australia
| | - Charles Hill
- School of Physics, University of Melbourne, Melbourne, Australia
| | - Joe Salfi
- Department of Electrical and Computer Engineering, The University of British Columbia, Vancouver BC V6T 1Z4, Canada
| | - Akira Oiwa
- The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047, Japan
- Center for Quantum Information and Quantum Biology, Institute for open and Transdisciplinary Research Initiative, Osaka University, 560-8531, Osaka, Japan
- Center for Spintronics Research Network (CSRN), Graduate School of Engineering Science, Osaka University, Osaka 560-8531, Japan
| | - Juha T Muhonen
- Department of Physics and Nanoscience Center, University of Jyväskylä, FI-40014 University of Jyväskylä, Finland
| | - Ewold Verhagen
- Center for Nanophotonics, AMOLF, 1098 XG, Amsterdam, The Netherlands
| | - M D LaHaye
- Department of Physics, Syracuse University, Syracuse, NY 13244-1130, United States of America
- Present Address: United States Air Force Research Laboratory, Rome, NY 13441, United States of America
| | - Hyun Ho Kim
- Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
- School of Materials Science and Engineering & Department of Energy Engineering Convergence, Kumoh National Institute of Technology, Gumi 39177, Korea
| | - Adam W Tsen
- Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Dimitrie Culcer
- School of Physics, The University of New South Wales, Sydney 2052, Australia
- Australian Research Council Centre of Excellence in Future Low-Energy Electronics Technologies, UNSW Node, The University of New South Wales, Sydney 2052, Australia
| | - Attila Geresdi
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, The Netherlands
| | - Jan A Mol
- School of Physics and Astronomy, Queen Mary University of London, E1 4NS, United Kingdom
| | - Varun Mohan
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States of America
| | - Prashant K Jain
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States of America
- Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States of America
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States of America
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States of America
| | - Jonathan Baugh
- Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
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13
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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 Lett 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] [What about the content of this article? (0)] [Affiliation(s)] [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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14
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Ma Dzik MT, Laucht A, Hudson FE, Jakob AM, Johnson BC, Jamieson DN, Itoh KM, Dzurak AS, Morello A. Conditional quantum operation of two exchange-coupled single-donor spin qubits in a MOS-compatible silicon device. Nat Commun 2021; 12:181. [PMID: 33420013 PMCID: PMC7794236 DOI: 10.1038/s41467-020-20424-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 12/02/2020] [Indexed: 11/09/2022] Open
Abstract
Silicon nanoelectronic devices can host single-qubit quantum logic operations with fidelity better than 99.9%. For the spins of an electron bound to a single-donor atom, introduced in the silicon by ion implantation, the quantum information can be stored for nearly 1 second. However, manufacturing a scalable quantum processor with this method is considered challenging, because of the exponential sensitivity of the exchange interaction that mediates the coupling between the qubits. Here we demonstrate the conditional, coherent control of an electron spin qubit in an exchange-coupled pair of 31P donors implanted in silicon. The coupling strength, J = 32.06 ± 0.06 MHz, is measured spectroscopically with high precision. Since the coupling is weaker than the electron-nuclear hyperfine coupling A ≈ 90 MHz which detunes the two electrons, a native two-qubit controlled-rotation gate can be obtained via a simple electron spin resonance pulse. This scheme is insensitive to the precise value of J, which makes it suitable for the scale-up of donor-based quantum computers in silicon that exploit the metal-oxide-semiconductor fabrication protocols commonly used in the classical electronics industry.
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Affiliation(s)
- Mateusz T Ma Dzik
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - Arne Laucht
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - Fay E Hudson
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - Alexander M Jakob
- Centre for Quantum Computation and Communication Technology, School of Physics, University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Brett C Johnson
- Centre for Quantum Computation and Communication Technology, School of Physics, University of Melbourne, Melbourne, VIC, 3010, Australia
| | - David N Jamieson
- Centre for Quantum Computation and Communication Technology, School of Physics, University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Kohei M Itoh
- School of Fundamental Science and Technology, Keio University, 3-14-1, Hiyoshi, 223-8522, Japan
| | - Andrew S Dzurak
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - Andrea Morello
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, NSW, 2052, Australia.
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15
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Gilbert W, Saraiva A, Lim WH, Yang CH, Laucht A, Bertrand B, Rambal N, Hutin L, Escott CC, Vinet M, Dzurak AS. Single-Electron Operation of a Silicon-CMOS 2 × 2 Quantum Dot Array with Integrated Charge Sensing. Nano Lett 2020; 20:7882-7888. [PMID: 33108202 DOI: 10.1021/acs.nanolett.0c02397] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The advanced nanoscale integration available in CMOS technology provides a key motivation for its use in spin-based quantum computing applications. Initial demonstrations of quantum dot formation and spin blockade in CMOS foundry-compatible devices are encouraging, but results are yet to match the control of individual electrons demonstrated in university-fabricated multigate designs. We show that quantum dots formed in a CMOS nanowire device can be measured with a remote single electron transistor (SET) formed in an adjacent nanowire, via floating coupling gates. By biasing the SET nanowire with respect to the nanowire hosting the quantum dots, we controllably form ancillary quantum dots under the floating gates, thus enabling control of all quantum dots in a 2 × 2 array, and charge sensing down to the last electron in each dot. We use effective mass theory to investigate the ideal geometrical parameters in order to achieve interdot tunnel rates required for spin-based quantum computation.
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Affiliation(s)
- Will Gilbert
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Andre Saraiva
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Wee Han Lim
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Chih Hwan Yang
- 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
| | - Benoit Bertrand
- Université Grenoble Alpes, CEA, LETI, 38000 Grenoble, France
| | - Nils Rambal
- Université Grenoble Alpes, CEA, LETI, 38000 Grenoble, France
| | - Louis Hutin
- Université Grenoble Alpes, CEA, LETI, 38000 Grenoble, France
| | - Christopher C Escott
- School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Maud Vinet
- Université Grenoble Alpes, CEA, LETI, 38000 Grenoble, France
| | - 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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16
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Mądzik MT, Ladd TD, Hudson FE, Itoh KM, Jakob AM, Johnson BC, McCallum JC, Jamieson DN, Dzurak AS, Laucht A, Morello A. Controllable freezing of the nuclear spin bath in a single-atom spin qubit. Sci Adv 2020; 6:6/27/eaba3442. [PMID: 32937454 PMCID: PMC7458445 DOI: 10.1126/sciadv.aba3442] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 05/22/2020] [Indexed: 06/11/2023]
Abstract
The quantum coherence and gate fidelity of electron spin qubits in semiconductors are often limited by nuclear spin fluctuations. Enrichment of spin-zero isotopes in silicon markedly improves the dephasing time [Formula: see text], which, unexpectedly, can extend two orders of magnitude beyond theoretical expectations. Using a single-atom 31P qubit in enriched 28Si, we show that the abnormally long [Formula: see text] is due to the freezing of the dynamics of the residual 29Si nuclei, caused by the electron-nuclear hyperfine interaction. Inserting a waiting period when the electron is controllably removed unfreezes the nuclear dynamics and restores the ergodic [Formula: see text] value. Our conclusions are supported by a nearly parameter-free modeling of the 29Si nuclear spin dynamics, which reveals the degree of backaction provided by the electron spin. This study clarifies the limits of ergodic assumptions in nuclear bath dynamics and provides previously unidentified strategies for maximizing coherence and gate fidelity of spin qubits in semiconductors.
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Affiliation(s)
- Mateusz T Mądzik
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Thaddeus D Ladd
- School of Physics, UNSW Sydney, Sydney, NSW 2052, Australia
- HRL Laboratories, LLC, 3011 Malibu Canyon Rd., Malibu, CA 90265, USA
| | - Fay E Hudson
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Kohei M Itoh
- School of Fundamental Science and Technology, Keio University, Kohoku-ku, Yokohama, Japan
| | - Alexander M Jakob
- Centre for Quantum Computation and Communication Technology, School of Physics, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Brett C Johnson
- Centre for Quantum Computation and Communication Technology, School of Physics, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Jeffrey C McCallum
- Centre for Quantum Computation and Communication Technology, School of Physics, University of Melbourne, Melbourne, VIC 3010, Australia
| | - David N Jamieson
- Centre for Quantum Computation and Communication Technology, School of Physics, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Andrew S Dzurak
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Arne Laucht
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Andrea Morello
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, NSW 2052, Australia.
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17
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Asaad S, Mourik V, Joecker B, Johnson MAI, Baczewski AD, Firgau HR, Mądzik MT, Schmitt V, Pla JJ, Hudson FE, Itoh KM, McCallum JC, Dzurak AS, Laucht A, Morello A. Coherent electrical control of a single high-spin nucleus in silicon. Nature 2020; 579:205-209. [PMID: 32161384 DOI: 10.1038/s41586-020-2057-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 01/30/2020] [Indexed: 11/09/2022]
Abstract
Nuclear spins are highly coherent quantum objects. In large ensembles, their control and detection via magnetic resonance is widely exploited, for example, in chemistry, medicine, materials science and mining. Nuclear spins also featured in early proposals for solid-state quantum computers1 and demonstrations of quantum search2 and factoring3 algorithms. Scaling up such concepts requires controlling individual nuclei, which can be detected when coupled to an electron4-6. However, the need to address the nuclei via oscillating magnetic fields complicates their integration in multi-spin nanoscale devices, because the field cannot be localized or screened. Control via electric fields would resolve this problem, but previous methods7-9 relied on transducing electric signals into magnetic fields via the electron-nuclear hyperfine interaction, which severely affects nuclear coherence. Here we demonstrate the coherent quantum control of a single 123Sb (spin-7/2) nucleus using localized electric fields produced within a silicon nanoelectronic device. The method exploits an idea proposed in 196110 but not previously realized experimentally with a single nucleus. Our results are quantitatively supported by a microscopic theoretical model that reveals how the purely electrical modulation of the nuclear electric quadrupole interaction results in coherent nuclear spin transitions that are uniquely addressable owing to lattice strain. The spin dephasing time, 0.1 seconds, is orders of magnitude longer than those obtained by methods that require a coupled electron spin to achieve electrical driving. These results show that high-spin quadrupolar nuclei could be deployed as chaotic models, strain sensors and hybrid spin-mechanical quantum systems using all-electrical controls. Integrating electrically controllable nuclei with quantum dots11,12 could pave the way to scalable, nuclear- and electron-spin-based quantum computers in silicon that operate without the need for oscillating magnetic fields.
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Affiliation(s)
- Serwan Asaad
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, New South Wales, Australia
| | - Vincent Mourik
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, New South Wales, Australia
| | - Benjamin Joecker
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, New South Wales, Australia
| | - Mark A I Johnson
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, New South Wales, Australia
| | - Andrew D Baczewski
- Center for Computing Research, Sandia National Laboratories, Albuquerque, NM, USA
| | - Hannes R Firgau
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, New South Wales, Australia
| | - Mateusz T Mądzik
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, New South Wales, Australia
| | - Vivien Schmitt
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, New South Wales, Australia
| | - Jarryd J Pla
- School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, New South Wales, Australia
| | - Fay E Hudson
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, New South Wales, Australia
| | - Kohei M Itoh
- School of Fundamental Science and Technology, Keio University, Yokohama, Japan
| | - Jeffrey C McCallum
- Centre for Quantum Computation and Communication Technology, School of Physics, University of Melbourne, Melbourne, Victoria, Australia
| | - Andrew S Dzurak
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, New South Wales, Australia
| | - Arne Laucht
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, New South Wales, Australia
| | - Andrea Morello
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, New South Wales, Australia.
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18
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Leon RCC, Yang CH, Hwang JCC, Lemyre JC, Tanttu T, Huang W, Chan KW, Tan KY, Hudson FE, Itoh KM, Morello A, Laucht A, Pioro-Ladrière M, Saraiva A, Dzurak AS. Coherent spin control of s-, p-, d- and f-electrons in a silicon quantum dot. Nat Commun 2020; 11:797. [PMID: 32047151 PMCID: PMC7012832 DOI: 10.1038/s41467-019-14053-w] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 12/11/2019] [Indexed: 11/09/2022] Open
Abstract
Once the periodic properties of elements were unveiled, chemical behaviour could be understood in terms of the valence of atoms. Ideally, this rationale would extend to quantum dots, and quantum computation could be performed by merely controlling the outer-shell electrons of dot-based qubits. Imperfections in semiconductor materials disrupt this analogy, so real devices seldom display a systematic many-electron arrangement. We demonstrate here an electrostatically confined quantum dot that reveals a well defined shell structure. We observe four shells (31 electrons) with multiplicities given by spin and valley degrees of freedom. Various fillings containing a single valence electron-namely 1, 5, 13 and 25 electrons-are found to be potential qubits. An integrated micromagnet allows us to perform electrically-driven spin resonance (EDSR), leading to faster Rabi rotations and higher fidelity single qubit gates at higher shell states. We investigate the impact of orbital excitations on single qubits as a function of the dot deformation and exploit it for faster qubit control.
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Affiliation(s)
- R C C Leon
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, The 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, The 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, The University of New South Wales, Sydney, NSW, 2052, Australia
- Research and Prototype Foundry, The University of Sydney, Sydney, NSW, 2006, Australia
| | - J Camirand Lemyre
- Institut Quantique et Département de Physique, Université de Sherbrooke, Sherbrooke, Québec, J1K 2R1, Canada
| | - T Tanttu
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - W Huang
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, The 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, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - K Y Tan
- QCD Labs COMP Centre of Excellence, Department of Applied Physics, Aalto University, 00076, Aalto, Finland
| | - F E Hudson
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - K M Itoh
- School of Fundamental Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohokuku, Yokohama, 223-8522, Japan
| | - A Morello
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - A Laucht
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - M Pioro-Ladrière
- Institut Quantique et Département de Physique, Université de Sherbrooke, Sherbrooke, Québec, J1K 2R1, Canada
- Quantum Information Science Program, Canadian Institute for Advanced Research, Toronto, ON, M5G 1Z8, Canada
| | - A Saraiva
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, The 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, The University of New South Wales, Sydney, NSW, 2052, Australia.
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19
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Hensen B, Wei Huang W, Yang CH, Wai Chan K, Yoneda J, Tanttu T, Hudson FE, Laucht A, Itoh KM, Ladd TD, Morello A, Dzurak AS. A silicon quantum-dot-coupled nuclear spin qubit. Nat Nanotechnol 2020; 15:13-17. [PMID: 31819245 DOI: 10.1038/s41565-019-0587-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 11/05/2019] [Indexed: 06/10/2023]
Abstract
Single nuclear spins in the solid state are a potential future platform for quantum computing1-3, because they possess long coherence times4-6 and offer excellent controllability7. Measurements can be performed via localized electrons, such as those in single atom dopants8,9 or crystal defects10-12. However, establishing long-range interactions between multiple dopants or defects is challenging13,14. Conversely, in lithographically defined quantum dots, tunable interdot electron tunnelling allows direct coupling of electron spin-based qubits in neighbouring dots15-20. Moreover, the compatibility with semiconductor fabrication techniques21 may allow for scaling to large numbers of qubits in the future. Unfortunately, hyperfine interactions are typically too weak to address single nuclei. Here we show that for electrons in silicon metal-oxide-semiconductor quantum dots the hyperfine interaction is sufficient to initialize, read out and control single 29Si nuclear spins. This approach combines the long coherence times of nuclear spins with the flexibility and scalability of quantum dot systems. We demonstrate high-fidelity projective readout and control of the nuclear spin qubit, as well as entanglement between the nuclear and electron spins. Crucially, we find that both the nuclear spin and electron spin retain their coherence while moving the electron between quantum dots. Hence we envision long-range nuclear-nuclear entanglement via electron shuttling3. Our results establish nuclear spins in quantum dots as a powerful new resource for quantum processing.
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Affiliation(s)
- Bas Hensen
- Center for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
- Delft University of Technology, Delft, The Netherlands
| | - Wister Wei Huang
- Center for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
| | - Chih-Hwan Yang
- Center for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
| | - Kok Wai Chan
- Center for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
| | - Jun Yoneda
- Center for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
| | - Tuomo Tanttu
- Center for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
| | - Fay E Hudson
- Center for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
| | - Arne Laucht
- Center for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
| | - Kohei M Itoh
- School of Fundamental Science and Technology, Keio University, Yokohama, Japan
| | | | - Andrea Morello
- Center for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia
| | - Andrew S Dzurak
- Center for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, New South Wales, Australia.
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20
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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21
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Laucht A, Kalra R, Simmons S, Dehollain JP, Muhonen JT, Mohiyaddin FA, Freer S, Hudson FE, Itoh KM, Jamieson DN, McCallum JC, Dzurak AS, Morello A. A dressed spin qubit in silicon. Nat Nanotechnol 2017; 12:61-66. [PMID: 27749833 DOI: 10.1038/nnano.2016.178] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2016] [Accepted: 08/17/2016] [Indexed: 06/06/2023]
Abstract
Coherent dressing of a quantum two-level system provides access to a new quantum system with improved properties-a different and easily tunable level splitting, faster control and longer coherence times. In our work we investigate the properties of the dressed, donor-bound electron spin in silicon, and assess its potential as a quantum bit in scalable architectures. The two dressed spin-polariton levels constitute a quantum bit that can be coherently driven with an oscillating magnetic field, an oscillating electric field, frequency modulation of the driving field or a simple detuning pulse. We measure coherence times of and , one order of magnitude longer than those of the undressed spin. Furthermore, the use of the dressed states enables coherent coupling of the solid-state spins to electric fields and mechanical oscillations.
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Affiliation(s)
- Arne Laucht
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Rachpon Kalra
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Stephanie Simmons
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Juan P Dehollain
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Juha T Muhonen
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Fahd A Mohiyaddin
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Solomon Freer
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Fay E Hudson
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Kohei M Itoh
- School of Fundamental Science and Technology, Keio University, 3-14-1 Hiyoshi, Kanagawa 223-8522, Japan
| | - David N Jamieson
- Centre for Quantum Computation and Communication Technology, School of Physics, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Jeffrey C McCallum
- Centre for Quantum Computation and Communication Technology, School of Physics, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Andrew S Dzurak
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - A Morello
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
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22
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Kalra R, Laucht A, Dehollain JP, Bar D, Freer S, Simmons S, Muhonen JT, Morello A. Vibration-induced electrical noise in a cryogen-free dilution refrigerator: Characterization, mitigation, and impact on qubit coherence. Rev Sci Instrum 2016; 87:073905. [PMID: 27475569 DOI: 10.1063/1.4959153] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Cryogen-free low-temperature setups are becoming more prominent in experimental science due to their convenience and reliability, and concern about the increasing scarcity of helium as a natural resource. Despite not having any moving parts at the cold end, pulse tube cryocoolers introduce vibrations that can be detrimental to the experiments. We characterize the coupling of these vibrations to the electrical signal observed on cables installed in a cryogen-free dilution refrigerator. The dominant electrical noise is in the 5-10 kHz range and its magnitude is found to be strongly temperature dependent. We test the performance of different cables designed to diagnose and tackle the noise, and find triboelectrics to be the dominant mechanism coupling the vibrations to the electrical signal. Flattening a semi-rigid cable or jacketing a flexible cable in order to restrict movement within the cable, successfully reduces the noise level by over an order of magnitude. Furthermore, we characterize the effect of the pulse tube vibrations on an electron spin qubit device in this setup. Coherence measurements are used to map out the spectrum of the noise experienced by the qubit, revealing spectral components matching the spectral signature of the pulse tube.
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Affiliation(s)
- Rachpon Kalra
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney NSW 2052, Australia
| | - Arne Laucht
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney NSW 2052, Australia
| | - Juan Pablo Dehollain
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney NSW 2052, Australia
| | - Daniel Bar
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney NSW 2052, Australia
| | - Solomon Freer
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney NSW 2052, Australia
| | - Stephanie Simmons
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney NSW 2052, Australia
| | - Juha T Muhonen
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney NSW 2052, Australia
| | - Andrea Morello
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney NSW 2052, Australia
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23
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Dehollain JP, Simmons S, Muhonen JT, Kalra R, Laucht A, Hudson F, Itoh KM, Jamieson DN, McCallum JC, Dzurak AS, Morello A. Bell's inequality violation with spins in silicon. Nat Nanotechnol 2016; 11:242-246. [PMID: 26571006 DOI: 10.1038/nnano.2015.262] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 10/07/2015] [Indexed: 06/05/2023]
Abstract
Bell's theorem proves the existence of entangled quantum states with no classical counterpart. An experimental violation of Bell's inequality demands simultaneously high fidelities in the preparation, manipulation and measurement of multipartite quantum entangled states, and provides a single-number benchmark for the performance of devices that use such states for quantum computing. We demonstrate a Bell/ Clauser-Horne-Shimony-Holt inequality violation with Bell signals up to 2.70(9), using the electron and the nuclear spins of a single phosphorus atom embedded in a silicon nanoelectronic device. Two-qubit state tomography reveals that our prepared states match the target maximally entangled Bell states with >96% fidelity. These experiments demonstrate complete control of the two-qubit Hilbert space of a phosphorus atom and highlight the important function of the nuclear qubit to expand the computational basis and maximize the readout fidelity.
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Affiliation(s)
- Juan P Dehollain
- Centre for Quantum Computation and Communication Technology, UNSW Australia, Sydney, New South Wales 2052, Australia
- School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Stephanie Simmons
- Centre for Quantum Computation and Communication Technology, UNSW Australia, Sydney, New South Wales 2052, Australia
- School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Juha T Muhonen
- Centre for Quantum Computation and Communication Technology, UNSW Australia, Sydney, New South Wales 2052, Australia
- School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Rachpon Kalra
- Centre for Quantum Computation and Communication Technology, UNSW Australia, Sydney, New South Wales 2052, Australia
- School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Arne Laucht
- Centre for Quantum Computation and Communication Technology, UNSW Australia, Sydney, New South Wales 2052, Australia
- School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Fay Hudson
- Centre for Quantum Computation and Communication Technology, UNSW Australia, Sydney, New South Wales 2052, Australia
- School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Kohei M Itoh
- School of Fundamental Science and Technology, Keio University, 3-14-1 Hiyoshi, 223-8522, Japan
| | - David N Jamieson
- Centre for Quantum Computation and Communication Technology, UNSW Australia, Sydney, New South Wales 2052, Australia
- School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Jeffrey C McCallum
- Centre for Quantum Computation and Communication Technology, UNSW Australia, Sydney, New South Wales 2052, Australia
- School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Andrew S Dzurak
- Centre for Quantum Computation and Communication Technology, UNSW Australia, Sydney, New South Wales 2052, Australia
- School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Andrea Morello
- Centre for Quantum Computation and Communication Technology, UNSW Australia, Sydney, New South Wales 2052, Australia
- School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
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24
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Muhonen JT, Laucht A, Simmons S, Dehollain JP, Kalra R, Hudson FE, Freer S, Itoh KM, Jamieson DN, McCallum JC, Dzurak AS, Morello A. Quantifying the quantum gate fidelity of single-atom spin qubits in silicon by randomized benchmarking. J Phys Condens Matter 2015; 27:154205. [PMID: 25783435 DOI: 10.1088/0953-8984/27/15/154205] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Building upon the demonstration of coherent control and single-shot readout of the electron and nuclear spins of individual (31)P atoms in silicon, we present here a systematic experimental estimate of quantum gate fidelities using randomized benchmarking of 1-qubit gates in the Clifford group. We apply this analysis to the electron and the ionized (31)P nucleus of a single P donor in isotopically purified (28)Si. We find average gate fidelities of 99.95% for the electron and 99.99% for the nuclear spin. These values are above certain error correction thresholds and demonstrate the potential of donor-based quantum computing in silicon. By studying the influence of the shape and power of the control pulses, we find evidence that the present limitation to the gate fidelity is mostly related to the external hardware and not the intrinsic behaviour of the qubit.
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Affiliation(s)
- J T Muhonen
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, NSW 2052, Australia
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25
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Laucht A, Muhonen JT, Mohiyaddin FA, Kalra R, Dehollain JP, Freer S, Hudson FE, Veldhorst M, Rahman R, Klimeck G, Itoh KM, Jamieson DN, McCallum JC, Dzurak AS, Morello A. Electrically controlling single-spin qubits in a continuous microwave field. Sci Adv 2015; 1:e1500022. [PMID: 26601166 PMCID: PMC4640634 DOI: 10.1126/sciadv.1500022] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 03/14/2015] [Indexed: 05/24/2023]
Abstract
Large-scale quantum computers must be built upon quantum bits that are both highly coherent and locally controllable. We demonstrate the quantum control of the electron and the nuclear spin of a single (31)P atom in silicon, using a continuous microwave magnetic field together with nanoscale electrostatic gates. The qubits are tuned into resonance with the microwave field by a local change in electric field, which induces a Stark shift of the qubit energies. This method, known as A-gate control, preserves the excellent coherence times and gate fidelities of isolated spins, and can be extended to arbitrarily many qubits without requiring multiple microwave sources.
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Affiliation(s)
- Arne Laucht
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Juha T. Muhonen
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Fahd A. Mohiyaddin
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Rachpon Kalra
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Juan P. Dehollain
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Solomon Freer
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Fay E. Hudson
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Menno Veldhorst
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Rajib Rahman
- Network for Computational Nanotechnology, Purdue University, West Lafayette, IN 47907, USA
| | - Gerhard Klimeck
- Network for Computational Nanotechnology, Purdue University, West Lafayette, IN 47907, USA
| | - Kohei M. Itoh
- School of Fundamental Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan
| | - David N. Jamieson
- Centre for Quantum Computation and Communication Technology, School of Physics, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Jeffrey C. McCallum
- Centre for Quantum Computation and Communication Technology, School of Physics, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Andrew S. Dzurak
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Andrea Morello
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales 2052, Australia
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26
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Muhonen JT, Dehollain JP, Laucht A, Hudson FE, Kalra R, Sekiguchi T, Itoh KM, Jamieson DN, McCallum JC, Dzurak AS, Morello A. Storing quantum information for 30 seconds in a nanoelectronic device. Nat Nanotechnol 2014; 9:986-91. [PMID: 25305745 DOI: 10.1038/nnano.2014.211] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 08/22/2014] [Indexed: 05/14/2023]
Abstract
The spin of an electron or a nucleus in a semiconductor naturally implements the unit of quantum information--the qubit. In addition, because semiconductors are currently used in the electronics industry, developing qubits in semiconductors would be a promising route to realize scalable quantum information devices. The solid-state environment, however, may provide deleterious interactions between the qubit and the nuclear spins of surrounding atoms, or charge and spin fluctuations arising from defects in oxides and interfaces. For materials such as silicon, enrichment of the spin-zero (28)Si isotope drastically reduces spin-bath decoherence. Experiments on bulk spin ensembles in (28)Si crystals have indeed demonstrated extraordinary coherence times. However, it remained unclear whether these would persist at the single-spin level, in gated nanostructures near amorphous interfaces. Here, we present the coherent operation of individual (31)P electron and nuclear spin qubits in a top-gated nanostructure, fabricated on an isotopically engineered (28)Si substrate. The (31)P nuclear spin sets the new benchmark coherence time (>30 s with Carr-Purcell-Meiboom-Gill (CPMG) sequence) of any single qubit in the solid state and reaches >99.99% control fidelity. The electron spin CPMG coherence time exceeds 0.5 s, and detailed noise spectroscopy indicates that--contrary to widespread belief--it is not limited by the proximity to an interface. Instead, decoherence is probably dominated by thermal and magnetic noise external to the device, and is thus amenable to further improvement.
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Affiliation(s)
- Juha T Muhonen
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Juan P Dehollain
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Arne Laucht
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Fay E Hudson
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Rachpon Kalra
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Takeharu Sekiguchi
- School of Fundamental Science and Technology, Keio University, 3-14-1 Hiyoshi, 223-8522, Japan
| | - Kohei M Itoh
- School of Fundamental Science and Technology, Keio University, 3-14-1 Hiyoshi, 223-8522, Japan
| | - David N Jamieson
- Centre for Quantum Computation and Communication Technology, School of Physics, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Jeffrey C McCallum
- Centre for Quantum Computation and Communication Technology, School of Physics, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Andrew S Dzurak
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Andrea Morello
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
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Laucht A, Hauke N, Villas-Bôas JM, Hofbauer F, Böhm G, Kaniber M, Finley JJ. Dephasing of exciton polaritons in photoexcited InGaAs quantum dots in GaAs nanocavities. Phys Rev Lett 2009; 103:087405. [PMID: 19792763 DOI: 10.1103/physrevlett.103.087405] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2009] [Revised: 07/13/2009] [Indexed: 05/28/2023]
Abstract
We present a combined experimental and theoretical study of the emission spectrum of zero dimensional nanocavity polaritons in electrically tunable single dot nanocavities. Such devices allow us to vary the dot-cavity detuning in situ and probe the emission spectrum under well-controlled conditions of lattice temperature and incoherent excitation level. Our results show that the observation of a double peak in the emission spectrum is not an unequivocal signature of strong coupling. Moreover, by comparing our results with theory, we extract the effective vacuum Rabi splitting, the pure dephasing rate, and their dependence on the incoherent optical pumping power and lattice temperature. Our study highlights how coupling to the lattice and dynamical fluctuations in the solid-state environment influence the coherence properties of quantum dot microcavity polaritons and, sometimes, may mask the occurrence of strong coupling.
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Affiliation(s)
- A Laucht
- Walter Schottky Institut, Technische Universität München, Am Coulombwall 3, D-85748 Garching, Germany
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