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Ungerer JH, Pally A, Kononov A, Lehmann S, Ridderbos J, Potts PP, Thelander C, Dick KA, Maisi VF, Scarlino P, Baumgartner A, Schönenberger C. Strong coupling between a microwave photon and a singlet-triplet qubit. Nat Commun 2024; 15:1068. [PMID: 38316779 PMCID: PMC10844229 DOI: 10.1038/s41467-024-45235-w] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 01/18/2024] [Indexed: 02/07/2024] Open
Abstract
Combining superconducting resonators and quantum dots has triggered tremendous progress in quantum information, however, attempts at coupling a resonator to even charge parity spin qubits have resulted only in weak spin-photon coupling. Here, we integrate a zincblende InAs nanowire double quantum dot with strong spin-orbit interaction in a magnetic-field resilient, high-quality resonator. The quantum confinement in the nanowire is achieved using deterministically grown wurtzite tunnel barriers. Our experiments on even charge parity states and at large magnetic fields, allow us to identify the relevant spin states and to measure the spin decoherence rates and spin-photon coupling strengths. We find an anti-crossing between the resonator mode in the single photon limit and a singlet-triplet qubit with a spin-photon coupling strength of g/2π = 139 ± 4 MHz. This coherent coupling exceeds the resonator decay rate κ/2π = 19.8 ± 0.2 MHz and the qubit dephasing rate γ/2π = 116 ± 7 MHz, putting our system in the strong coupling regime.
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Affiliation(s)
- J H Ungerer
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland.
- Swiss Nanoscience Institute, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland.
| | - A Pally
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland.
| | - A Kononov
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland
| | - S Lehmann
- Solid State Physics and NanoLund, Lund University, Box 118, S-22100, Lund, Sweden
| | - J Ridderbos
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland
- MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands
| | - P P Potts
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland
- Swiss Nanoscience Institute, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland
| | - C Thelander
- Solid State Physics and NanoLund, Lund University, Box 118, S-22100, Lund, Sweden
| | - K A Dick
- Centre for Analysis and Synthesis, Lund University, Box 124, S-22100, Lund, Sweden
| | - V F Maisi
- Solid State Physics and NanoLund, Lund University, Box 118, S-22100, Lund, Sweden
| | - P Scarlino
- Institute of Physics and Center for Quantum Science and Engineering, Ecole Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland
| | - A Baumgartner
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland
- Swiss Nanoscience Institute, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland
| | - C Schönenberger
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland
- Swiss Nanoscience Institute, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland
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Landig AJ, Koski JV, Scarlino P, Reichl C, Wegscheider W, Wallraff A, Ensslin K, Ihn T. Microwave-Cavity-Detected Spin Blockade in a Few-Electron Double Quantum Dot. Phys Rev Lett 2019; 122:213601. [PMID: 31283346 DOI: 10.1103/physrevlett.122.213601] [Citation(s) in RCA: 1] [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: 11/09/2018] [Indexed: 06/09/2023]
Abstract
We investigate spin states of few electrons in a double quantum dot by coupling them to a magnetic field resilient NbTiN microwave resonator. The electric field of the resonator couples to the electric dipole moment of the charge states in the double dot. For a two-electron state the spin-triplet state has a vanishing electric dipole moment and can therefore be distinguished from the spin-singlet state. This way the charge dipole sensitivity of the resonator response is converted to a spin selectivity. We thereby investigate Pauli spin blockade known from transport experiments at finite source-drain bias. In addition we find an unconventional spin-blockade triggered by the absorption of resonator photons.
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Affiliation(s)
- A J Landig
- Department of Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - J V Koski
- Department of Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - P Scarlino
- Department of Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - C Reichl
- Department of Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - W Wegscheider
- Department of Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - A Wallraff
- Department of Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - K Ensslin
- Department of Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - T Ihn
- Department of Physics, ETH Zürich, CH-8093 Zürich, Switzerland
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3
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Scarlino P, van Woerkom DJ, Stockklauser A, Koski JV, Collodo MC, Gasparinetti S, Reichl C, Wegscheider W, Ihn T, Ensslin K, Wallraff A. All-Microwave Control and Dispersive Readout of Gate-Defined Quantum Dot Qubits in Circuit Quantum Electrodynamics. Phys Rev Lett 2019; 122:206802. [PMID: 31172788 DOI: 10.1103/physrevlett.122.206802] [Citation(s) in RCA: 5] [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: 11/14/2017] [Revised: 01/31/2019] [Indexed: 05/27/2023]
Abstract
Developing fast and accurate control and readout techniques is an important challenge in quantum information processing with semiconductor qubits. Here, we study the dynamics and the coherence properties of a GaAs/AlGaAs double quantum dot charge qubit strongly coupled to a frequency-tunable high-impedance resonator. We drive qubit transitions with synthesized microwave pulses and perform qubit readout through the state-dependent frequency shift imparted by the qubit on the dispersively coupled resonator. We perform Rabi oscillation, Ramsey fringe, energy relaxation, and Hahn-echo measurements and find significantly reduced decoherence rates down to γ_{2}/2π∼3 MHz corresponding to coherence times of up to T_{2}∼50 ns for charge states in gate-defined quantum dot qubits. We realize Rabi π pulses of width down to σ∼0.25 ns.
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Affiliation(s)
- P Scarlino
- Department of Physics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - D J van Woerkom
- Department of Physics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - A Stockklauser
- Department of Physics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - J V Koski
- Department of Physics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - M C Collodo
- Department of Physics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - S Gasparinetti
- Department of Physics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - C Reichl
- Department of Physics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - W Wegscheider
- Department of Physics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - T Ihn
- Department of Physics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - K Ensslin
- Department of Physics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - A Wallraff
- Department of Physics, ETH Zurich, CH-8093 Zurich, Switzerland
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4
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Koski JV, Landig AJ, Pályi A, Scarlino P, Reichl C, Wegscheider W, Burkard G, Wallraff A, Ensslin K, Ihn T. Floquet Spectroscopy of a Strongly Driven Quantum Dot Charge Qubit with a Microwave Resonator. Phys Rev Lett 2018; 121:043603. [PMID: 30095954 DOI: 10.1103/physrevlett.121.043603] [Citation(s) in RCA: 2] [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: 02/08/2018] [Indexed: 06/08/2023]
Abstract
We experimentally investigate a strongly driven GaAs double quantum dot charge qubit weakly coupled to a superconducting microwave resonator. The Floquet states emerging from strong driving are probed by tracing the qubit-resonator resonance condition. In this way, we probe the resonance of a qubit that is driven in an adiabatic, a nonadiabatic, or an intermediate rate, showing distinct quantum features of multiphoton processes and a fringe pattern similar to Landau-Zener-Stückelberg interference. Our resonant detection scheme enables the investigation of novel features when the drive frequency is comparable to the resonator frequency. Models based on the adiabatic approximation, rotating wave approximation, and Floquet theory explain our experimental observations.
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Affiliation(s)
- J V Koski
- Department of Physics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - A J Landig
- Department of Physics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - A Pályi
- Department of Physics, Budapest University of Technology and Economics, H-1111 Budapest, Hungary
- MTA-BME Exotic Quantum Phases "Momentum" Research Group, Budapest University of Technology and Economics, H-1111 Budapest, Hungary
| | - P Scarlino
- Department of Physics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - C Reichl
- Department of Physics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - W Wegscheider
- Department of Physics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - G Burkard
- Department of Physics, University of Konstanz, D-78457 Konstanz, Germany
| | - A Wallraff
- Department of Physics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - K Ensslin
- Department of Physics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - T Ihn
- Department of Physics, ETH Zurich, CH-8093 Zurich, Switzerland
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5
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Landig AJ, Koski JV, Scarlino P, Mendes UC, Blais A, Reichl C, Wegscheider W, Wallraff A, Ensslin K, Ihn T. Coherent spin-photon coupling using a resonant exchange qubit. Nature 2018; 560:179-184. [PMID: 30046114 DOI: 10.1038/s41586-018-0365-y] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 06/19/2018] [Indexed: 11/09/2022]
Abstract
Electron spins hold great promise for quantum computation because of their long coherence times. Long-distance coherent coupling of spins is a crucial step towards quantum information processing with spin qubits. One approach to realizing interactions between distant spin qubits is to use photons as carriers of quantum information. Here we demonstrate strong coupling between single microwave photons in a niobium titanium nitride high-impedance resonator and a three-electron spin qubit (also known as a resonant exchange qubit) in a gallium arsenide device consisting of three quantum dots. We observe the vacuum Rabi mode splitting of the resonance of the resonator, which is a signature of strong coupling; specifically, we observe a coherent coupling strength of about 31 megahertz and a qubit decoherence rate of about 20 megahertz. We can tune the decoherence electrostatically to obtain a minimal decoherence rate of around 10 megahertz for a coupling strength of around 23 megahertz. We directly measure the dependence of the qubit-photon coupling strength on the tunable electric dipole moment of the qubit using the 'AC Stark' effect. Our demonstration of strong qubit-photon coupling for a three-electron spin qubit is an important step towards coherent long-distance coupling of spin qubits.
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Affiliation(s)
- A J Landig
- Department of Physics, ETH Zürich, Zurich, Switzerland.
| | - J V Koski
- Department of Physics, ETH Zürich, Zurich, Switzerland
| | - P Scarlino
- Department of Physics, ETH Zürich, Zurich, Switzerland
| | - U C Mendes
- Institut quantique and Départment de Physique, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - A Blais
- Institut quantique and Départment de Physique, Université de Sherbrooke, Sherbrooke, Quebec, Canada.,Canadian Institute for Advanced Research, Toronto, Ontario, Canada
| | - C Reichl
- Department of Physics, ETH Zürich, Zurich, Switzerland
| | - W Wegscheider
- Department of Physics, ETH Zürich, Zurich, Switzerland
| | - A Wallraff
- Department of Physics, ETH Zürich, Zurich, Switzerland
| | - K Ensslin
- Department of Physics, ETH Zürich, Zurich, Switzerland
| | - T Ihn
- Department of Physics, ETH Zürich, Zurich, Switzerland
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6
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Watson TF, Philips SGJ, Kawakami E, Ward DR, Scarlino P, Veldhorst M, Savage DE, Lagally MG, Friesen M, Coppersmith SN, Eriksson MA, Vandersypen LMK. A programmable two-qubit quantum processor in silicon. Nature 2018; 555:633-637. [PMID: 29443962 DOI: 10.1038/nature25766] [Citation(s) in RCA: 433] [Impact Index Per Article: 72.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Accepted: 01/16/2018] [Indexed: 12/18/2022]
Abstract
Now that it is possible to achieve measurement and control fidelities for individual quantum bits (qubits) above the threshold for fault tolerance, attention is moving towards the difficult task of scaling up the number of physical qubits to the large numbers that are needed for fault-tolerant quantum computing. In this context, quantum-dot-based spin qubits could have substantial advantages over other types of qubit owing to their potential for all-electrical operation and ability to be integrated at high density onto an industrial platform. Initialization, readout and single- and two-qubit gates have been demonstrated in various quantum-dot-based qubit representations. However, as seen with small-scale demonstrations of quantum computers using other types of qubit, combining these elements leads to challenges related to qubit crosstalk, state leakage, calibration and control hardware. Here we overcome these challenges by using carefully designed control techniques to demonstrate a programmable two-qubit quantum processor in a silicon device that can perform the Deutsch-Josza algorithm and the Grover search algorithm-canonical examples of quantum algorithms that outperform their classical analogues. We characterize the entanglement in our processor by using quantum-state tomography of Bell states, measuring state fidelities of 85-89 per cent and concurrences of 73-82 per cent. These results pave the way for larger-scale quantum computers that use spins confined to quantum dots.
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Affiliation(s)
- T F Watson
- QuTech and the Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, The Netherlands
| | - S G J Philips
- QuTech and the Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, The Netherlands
| | - E Kawakami
- QuTech and the Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, The Netherlands
| | - D R Ward
- University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - P Scarlino
- QuTech and the Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, The Netherlands
| | - M Veldhorst
- QuTech and the Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, The Netherlands
| | - D E Savage
- University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - M G Lagally
- University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Mark Friesen
- University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - S N Coppersmith
- University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - M A Eriksson
- University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - L M K Vandersypen
- QuTech and the Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, The Netherlands
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7
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Scarlino P, Kawakami E, Ward DR, Savage DE, Lagally MG, Friesen M, Coppersmith SN, Eriksson MA, Vandersypen LMK. Second-Harmonic Coherent Driving of a Spin Qubit in a Si/SiGe Quantum Dot. Phys Rev Lett 2015; 115:106802. [PMID: 26382693 DOI: 10.1103/physrevlett.115.106802] [Citation(s) in RCA: 2] [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: 04/24/2015] [Indexed: 06/05/2023]
Abstract
We demonstrate coherent driving of a single electron spin using second-harmonic excitation in a Si/SiGe quantum dot. Our estimates suggest that the anharmonic dot confining potential combined with a gradient in the transverse magnetic field dominates the second-harmonic response. As expected, the Rabi frequency depends quadratically on the driving amplitude, and the periodicity with respect to the phase of the drive is twice that of the fundamental harmonic. The maximum Rabi frequency observed for the second harmonic is just a factor of 2 lower than that achieved for the first harmonic when driving at the same power. Combined with the lower demands on microwave circuitry when operating at half the qubit frequency, these observations indicate that second-harmonic driving can be a useful technique for future quantum computation architectures.
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Affiliation(s)
- P Scarlino
- Kavli Institute of Nanoscience, TU Delft, Lorentzweg 1, 2628 CJ Delft, Netherlands
| | - E Kawakami
- Kavli Institute of Nanoscience, TU Delft, Lorentzweg 1, 2628 CJ Delft, Netherlands
| | - D R Ward
- University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - D E Savage
- University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - M G Lagally
- University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Mark Friesen
- University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - S N Coppersmith
- University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - M A Eriksson
- University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - L M K Vandersypen
- Kavli Institute of Nanoscience, TU Delft, Lorentzweg 1, 2628 CJ Delft, Netherlands
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8
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Scarlino P, Kawakami E, Stano P, Shafiei M, Reichl C, Wegscheider W, Vandersypen LMK. Spin-relaxation anisotropy in a GaAs quantum dot. Phys Rev Lett 2014; 113:256802. [PMID: 25554903 DOI: 10.1103/physrevlett.113.256802] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Indexed: 06/04/2023]
Abstract
We report that the electron spin-relaxation time T_{1} in a GaAs quantum dot with a spin-1/2 ground state has a 180° periodicity in the orientation of the in-plane magnetic field. This periodicity has been predicted for circular dots as being due to the interplay of Rashba and Dresselhaus spin orbit contributions. Different from this prediction, we find that the extrema in the T_{1} do not occur when the magnetic field is along the [110] and [11[over ¯]0] crystallographic directions. This deviation is attributed to an elliptical dot confining potential. The T_{1} varies by more than 1 order of magnitude when rotating a 3 T field, reaching about 80 ms for the optimal angle. We infer from the data that in our device the signs of the Rashba and Dresselhaus constants are opposite.
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Affiliation(s)
- P Scarlino
- Kavli Institute of Nanoscience, TU Delft, Lorentzweg 1, 2628 CJ Delft, Netherlands
| | - E Kawakami
- Kavli Institute of Nanoscience, TU Delft, Lorentzweg 1, 2628 CJ Delft, Netherlands
| | - P Stano
- RIKEN Center for Emergent Matter Science, Wako-shi, Saitama 351-0198, Japan and Institute of Physics, Slovak Academy of Sciences, Dubravska cesta 9, 84511 Bratislava, Slovakia
| | - M Shafiei
- Kavli Institute of Nanoscience, TU Delft, Lorentzweg 1, 2628 CJ Delft, Netherlands
| | - C Reichl
- Solid State Physics Laboratory, ETH Zurich, Schafmattstrasse 16, 8093 Zurich, Switzerland
| | - W Wegscheider
- Solid State Physics Laboratory, ETH Zurich, Schafmattstrasse 16, 8093 Zurich, Switzerland
| | - L M K Vandersypen
- Kavli Institute of Nanoscience, TU Delft, Lorentzweg 1, 2628 CJ Delft, Netherlands
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9
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Kawakami E, Scarlino P, Ward DR, Braakman FR, Savage DE, Lagally MG, Friesen M, Coppersmith SN, Eriksson MA, Vandersypen LMK. Electrical control of a long-lived spin qubit in a Si/SiGe quantum dot. Nat Nanotechnol 2014; 9:666-670. [PMID: 25108810 DOI: 10.1038/nnano.2014.153] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 06/27/2014] [Indexed: 06/03/2023]
Abstract
Nanofabricated quantum bits permit large-scale integration but usually suffer from short coherence times due to interactions with their solid-state environment. The outstanding challenge is to engineer the environment so that it minimally affects the qubit, but still allows qubit control and scalability. Here, we demonstrate a long-lived single-electron spin qubit in a Si/SiGe quantum dot with all-electrical two-axis control. The spin is driven by resonant microwave electric fields in a transverse magnetic field gradient from a local micromagnet, and the spin state is read out in the single-shot mode. Electron spin resonance occurs at two closely spaced frequencies, which we attribute to two valley states. Thanks to the weak hyperfine coupling in silicon, a Ramsey decay timescale of 1 μs is observed, almost two orders of magnitude longer than the intrinsic timescales in GaAs quantum dots, whereas gate operation times are comparable to those reported in GaAs. The spin echo decay time is ~40 μs, both with one and four echo pulses, possibly limited by intervalley scattering. These advances strongly improve the prospects for quantum information processing based on quantum dots.
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Affiliation(s)
- E Kawakami
- 1] Kavli Institute of Nanoscience, TU Delft, Lorentzweg 1, 2628 CJ Delft, The Netherlands [2]
| | - P Scarlino
- 1] Kavli Institute of Nanoscience, TU Delft, Lorentzweg 1, 2628 CJ Delft, The Netherlands [2]
| | - D R Ward
- University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - F R Braakman
- 1] Kavli Institute of Nanoscience, TU Delft, Lorentzweg 1, 2628 CJ Delft, The Netherlands [2]
| | - D E Savage
- University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - M G Lagally
- University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Mark Friesen
- University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - S N Coppersmith
- University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - M A Eriksson
- University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - L M K Vandersypen
- Kavli Institute of Nanoscience, TU Delft, Lorentzweg 1, 2628 CJ Delft, The Netherlands
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