1
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Foxen B, Neill C, Dunsworth A, Roushan P, Chiaro B, Megrant A, Kelly J, Chen Z, Satzinger K, Barends R, Arute F, Arya K, Babbush R, Bacon D, Bardin JC, Boixo S, Buell D, Burkett B, Chen Y, Collins R, Farhi E, Fowler A, Gidney C, Giustina M, Graff R, Harrigan M, Huang T, Isakov SV, Jeffrey E, Jiang Z, Kafri D, Kechedzhi K, Klimov P, Korotkov A, Kostritsa F, Landhuis D, Lucero E, McClean J, McEwen M, Mi X, Mohseni M, Mutus JY, Naaman O, Neeley M, Niu M, Petukhov A, Quintana C, Rubin N, Sank D, Smelyanskiy V, Vainsencher A, White TC, Yao Z, Yeh P, Zalcman A, Neven H, Martinis JM. Demonstrating a Continuous Set of Two-Qubit Gates for Near-Term Quantum Algorithms. Phys Rev Lett 2020; 125:120504. [PMID: 33016760 DOI: 10.1103/physrevlett.125.120504] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 06/27/2020] [Accepted: 07/22/2020] [Indexed: 06/11/2023]
Abstract
Quantum algorithms offer a dramatic speedup for computational problems in material science and chemistry. However, any near-term realizations of these algorithms will need to be optimized to fit within the finite resources offered by existing noisy hardware. Here, taking advantage of the adjustable coupling of gmon qubits, we demonstrate a continuous two-qubit gate set that can provide a threefold reduction in circuit depth as compared to a standard decomposition. We implement two gate families: an imaginary swap-like (iSWAP-like) gate to attain an arbitrary swap angle, θ, and a controlled-phase gate that generates an arbitrary conditional phase, ϕ. Using one of each of these gates, we can perform an arbitrary two-qubit gate within the excitation-preserving subspace allowing for a complete implementation of the so-called Fermionic simulation (fSim) gate set. We benchmark the fidelity of the iSWAP-like and controlled-phase gate families as well as 525 other fSim gates spread evenly across the entire fSim(θ,ϕ) parameter space, achieving a purity-limited average two-qubit Pauli error of 3.8×10^{-3} per fSim gate.
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Affiliation(s)
- B Foxen
- Department of Physics, University of California, Santa Barbara, California 93106, USA
- Google Research, Santa Barbara, California 93117, USA
| | - C Neill
- Google Research, Santa Barbara, California 93117, USA
| | - A Dunsworth
- Google Research, Santa Barbara, California 93117, USA
| | - P Roushan
- Google Research, Santa Barbara, California 93117, USA
| | - B Chiaro
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - A Megrant
- Google Research, Santa Barbara, California 93117, USA
| | - J Kelly
- Google Research, Santa Barbara, California 93117, USA
| | - Zijun Chen
- Google Research, Santa Barbara, California 93117, USA
| | - K Satzinger
- Google Research, Santa Barbara, California 93117, USA
| | - R Barends
- Google Research, Santa Barbara, California 93117, USA
| | - F Arute
- Google Research, Santa Barbara, California 93117, USA
| | - K Arya
- Google Research, Santa Barbara, California 93117, USA
| | - R Babbush
- Google Research, Santa Barbara, California 93117, USA
| | - D Bacon
- Google Research, Santa Barbara, California 93117, USA
| | - J C Bardin
- Google Research, Santa Barbara, California 93117, USA
- Department of Electrical and Computer Engineering, University of Massachusetts-Amherst, Amherst, Massachusetts 01003, USA
| | - S Boixo
- Google Research, Santa Barbara, California 93117, USA
| | - D Buell
- Google Research, Santa Barbara, California 93117, USA
| | - B Burkett
- Google Research, Santa Barbara, California 93117, USA
| | - Yu Chen
- Google Research, Santa Barbara, California 93117, USA
| | - R Collins
- Google Research, Santa Barbara, California 93117, USA
| | - E Farhi
- Google Research, Santa Barbara, California 93117, USA
| | - A Fowler
- Google Research, Santa Barbara, California 93117, USA
| | - C Gidney
- Google Research, Santa Barbara, California 93117, USA
| | - M Giustina
- Google Research, Santa Barbara, California 93117, USA
| | - R Graff
- Google Research, Santa Barbara, California 93117, USA
| | - M Harrigan
- Google Research, Santa Barbara, California 93117, USA
| | - T Huang
- Google Research, Santa Barbara, California 93117, USA
| | - S V Isakov
- Google Research, Santa Barbara, California 93117, USA
| | - E Jeffrey
- Google Research, Santa Barbara, California 93117, USA
| | - Z Jiang
- Google Research, Santa Barbara, California 93117, USA
| | - D Kafri
- Google Research, Santa Barbara, California 93117, USA
| | - K Kechedzhi
- Google Research, Santa Barbara, California 93117, USA
| | - P Klimov
- Google Research, Santa Barbara, California 93117, USA
| | - A Korotkov
- Google Research, Santa Barbara, California 93117, USA
| | - F Kostritsa
- Google Research, Santa Barbara, California 93117, USA
| | - D Landhuis
- Google Research, Santa Barbara, California 93117, USA
| | - E Lucero
- Google Research, Santa Barbara, California 93117, USA
| | - J McClean
- Google Research, Santa Barbara, California 93117, USA
| | - M McEwen
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - X Mi
- Google Research, Santa Barbara, California 93117, USA
| | - M Mohseni
- Google Research, Santa Barbara, California 93117, USA
| | - J Y Mutus
- Google Research, Santa Barbara, California 93117, USA
| | - O Naaman
- Google Research, Santa Barbara, California 93117, USA
| | - M Neeley
- Google Research, Santa Barbara, California 93117, USA
| | - M Niu
- Google Research, Santa Barbara, California 93117, USA
| | - A Petukhov
- Google Research, Santa Barbara, California 93117, USA
| | - C Quintana
- Google Research, Santa Barbara, California 93117, USA
| | - N Rubin
- Google Research, Santa Barbara, California 93117, USA
| | - D Sank
- Google Research, Santa Barbara, California 93117, USA
| | - V Smelyanskiy
- Google Research, Santa Barbara, California 93117, USA
| | - A Vainsencher
- Google Research, Santa Barbara, California 93117, USA
| | - T C White
- Google Research, Santa Barbara, California 93117, USA
| | - Z Yao
- Google Research, Santa Barbara, California 93117, USA
| | - P Yeh
- Google Research, Santa Barbara, California 93117, USA
| | - A Zalcman
- Google Research, Santa Barbara, California 93117, USA
| | - H Neven
- Google Research, Santa Barbara, California 93117, USA
| | - J M Martinis
- Department of Physics, University of California, Santa Barbara, California 93106, USA
- Google Research, Santa Barbara, California 93117, USA
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2
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Klimov PV, Kelly J, Chen Z, Neeley M, Megrant A, Burkett B, Barends R, Arya K, Chiaro B, Chen Y, Dunsworth A, Fowler A, Foxen B, Gidney C, Giustina M, Graff R, Huang T, Jeffrey E, Lucero E, Mutus JY, Naaman O, Neill C, Quintana C, Roushan P, Sank D, Vainsencher A, Wenner J, White TC, Boixo S, Babbush R, Smelyanskiy VN, Neven H, Martinis JM. Fluctuations of Energy-Relaxation Times in Superconducting Qubits. Phys Rev Lett 2018; 121:090502. [PMID: 30230854 DOI: 10.1103/physrevlett.121.090502] [Citation(s) in RCA: 14] [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: 05/18/2018] [Indexed: 06/08/2023]
Abstract
Superconducting qubits are an attractive platform for quantum computing since they have demonstrated high-fidelity quantum gates and extensibility to modest system sizes. Nonetheless, an outstanding challenge is stabilizing their energy-relaxation times, which can fluctuate unpredictably in frequency and time. Here, we use qubits as spectral and temporal probes of individual two-level-system defects to provide direct evidence that they are responsible for the largest fluctuations. This research lays the foundation for stabilizing qubit performance through calibration, design, and fabrication.
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Affiliation(s)
- P V Klimov
- Google, Santa Barbara, California 93117, USA
| | - J Kelly
- Google, Santa Barbara, California 93117, USA
| | - Z Chen
- Google, Santa Barbara, California 93117, USA
| | - M Neeley
- Google, Santa Barbara, California 93117, USA
| | - A Megrant
- Google, Santa Barbara, California 93117, USA
| | - B Burkett
- Google, Santa Barbara, California 93117, USA
| | - R Barends
- Google, Santa Barbara, California 93117, USA
| | - K Arya
- Google, Santa Barbara, California 93117, USA
| | - B Chiaro
- University of California, Santa Barbara, California 93106, USA
| | - Yu Chen
- Google, Santa Barbara, California 93117, USA
| | - A Dunsworth
- University of California, Santa Barbara, California 93106, USA
| | - A Fowler
- Google, Santa Barbara, California 93117, USA
| | - B Foxen
- University of California, Santa Barbara, California 93106, USA
| | - C Gidney
- Google, Santa Barbara, California 93117, USA
| | - M Giustina
- Google, Santa Barbara, California 93117, USA
| | - R Graff
- Google, Santa Barbara, California 93117, USA
| | - T Huang
- Google, Santa Barbara, California 93117, USA
| | - E Jeffrey
- Google, Santa Barbara, California 93117, USA
| | - Erik Lucero
- Google, Santa Barbara, California 93117, USA
| | - J Y Mutus
- Google, Santa Barbara, California 93117, USA
| | - O Naaman
- Google, Santa Barbara, California 93117, USA
| | - C Neill
- Google, Santa Barbara, California 93117, USA
| | - C Quintana
- Google, Santa Barbara, California 93117, USA
| | - P Roushan
- Google, Santa Barbara, California 93117, USA
| | - Daniel Sank
- Google, Santa Barbara, California 93117, USA
| | | | - J Wenner
- University of California, Santa Barbara, California 93106, USA
| | - T C White
- Google, Santa Barbara, California 93117, USA
| | - S Boixo
- Google, Los Angeles, California 90291, USA
| | - R Babbush
- Google, Los Angeles, California 90291, USA
| | | | - H Neven
- Google, Los Angeles, California 90291, USA
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3
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Quintana CM, Chen Y, Sank D, Petukhov AG, White TC, Kafri D, Chiaro B, Megrant A, Barends R, Campbell B, Chen Z, Dunsworth A, Fowler AG, Graff R, Jeffrey E, Kelly J, Lucero E, Mutus JY, Neeley M, Neill C, O'Malley PJJ, Roushan P, Shabani A, Smelyanskiy VN, Vainsencher A, Wenner J, Neven H, Martinis JM. Observation of Classical-Quantum Crossover of 1/f Flux Noise and Its Paramagnetic Temperature Dependence. Phys Rev Lett 2017; 118:057702. [PMID: 28211704 DOI: 10.1103/physrevlett.118.057702] [Citation(s) in RCA: 16] [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: 09/05/2016] [Indexed: 06/06/2023]
Abstract
By analyzing the dissipative dynamics of a tunable gap flux qubit, we extract both sides of its two-sided environmental flux noise spectral density over a range of frequencies around 2k_{B}T/h≈1 GHz, allowing for the observation of a classical-quantum crossover. Below the crossover point, the symmetric noise component follows a 1/f power law that matches the magnitude of the 1/f noise near 1 Hz. The antisymmetric component displays a 1/T dependence below 100 mK, providing dynamical evidence for a paramagnetic environment. Extrapolating the two-sided spectrum predicts the linewidth and reorganization energy of incoherent resonant tunneling between flux qubit wells.
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Affiliation(s)
- C M Quintana
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - Yu Chen
- Google Inc., Santa Barbara, California 93117, USA
| | - D Sank
- Google Inc., Santa Barbara, California 93117, USA
| | - A G Petukhov
- NASA Ames Research Center, Moffett Field, California 94035, USA
| | - T C White
- Google Inc., Santa Barbara, California 93117, USA
| | - Dvir Kafri
- Google Inc., Venice, California 90291, USA
| | - B Chiaro
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - A Megrant
- Google Inc., Santa Barbara, California 93117, USA
| | - R Barends
- Google Inc., Santa Barbara, California 93117, USA
| | - B Campbell
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - Z Chen
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - A Dunsworth
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - A G Fowler
- Google Inc., Santa Barbara, California 93117, USA
| | - R Graff
- Google Inc., Santa Barbara, California 93117, USA
| | - E Jeffrey
- Google Inc., Santa Barbara, California 93117, USA
| | - J Kelly
- Google Inc., Santa Barbara, California 93117, USA
| | - E Lucero
- Google Inc., Santa Barbara, California 93117, USA
| | - J Y Mutus
- Google Inc., Santa Barbara, California 93117, USA
| | - M Neeley
- Google Inc., Santa Barbara, California 93117, USA
| | - C Neill
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - P J J O'Malley
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - P Roushan
- Google Inc., Santa Barbara, California 93117, USA
| | - A Shabani
- Google Inc., Venice, California 90291, USA
| | | | | | - J Wenner
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - H Neven
- Google Inc., Venice, California 90291, USA
| | - John M Martinis
- Department of Physics, University of California, Santa Barbara, California 93106, USA
- Google Inc., Santa Barbara, California 93117, USA
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4
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Barends R, Lamata L, Kelly J, García-Álvarez L, Fowler AG, Megrant A, Jeffrey E, White TC, Sank D, Mutus JY, Campbell B, Chen Y, Chen Z, Chiaro B, Dunsworth A, Hoi IC, Neill C, O'Malley PJJ, Quintana C, Roushan P, Vainsencher A, Wenner J, Solano E, Martinis JM. Digital quantum simulation of fermionic models with a superconducting circuit. Nat Commun 2015; 6:7654. [PMID: 26153660 PMCID: PMC4510643 DOI: 10.1038/ncomms8654] [Citation(s) in RCA: 214] [Impact Index Per Article: 23.8] [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: 03/16/2015] [Accepted: 05/24/2015] [Indexed: 12/20/2022] Open
Abstract
One of the key applications of quantum information is simulating nature. Fermions are ubiquitous in nature, appearing in condensed matter systems, chemistry and high energy physics. However, universally simulating their interactions is arguably one of the largest challenges, because of the difficulties arising from anticommutativity. Here we use digital methods to construct the required arbitrary interactions, and perform quantum simulation of up to four fermionic modes with a superconducting quantum circuit. We employ in excess of 300 quantum logic gates, and reach fidelities that are consistent with a simple model of uncorrelated errors. The presented approach is in principle scalable to a larger number of modes, and arbitrary spatial dimensions.
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Affiliation(s)
- R Barends
- Google Inc., Santa Barbara, California 93117, USA
| | - L Lamata
- Department of Physical Chemistry, University of the Basque Country UPV/EHU, Apartado 644, Bilbao E-48080, Spain
| | - J Kelly
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - L García-Álvarez
- Department of Physical Chemistry, University of the Basque Country UPV/EHU, Apartado 644, Bilbao E-48080, Spain
| | - A G Fowler
- Google Inc., Santa Barbara, California 93117, USA
| | - A Megrant
- 1] Department of Physics, University of California, Santa Barbara, California 93106, USA. [2] Department of Materials, University of California, Santa Barbara, California 93106, USA
| | - E Jeffrey
- Google Inc., Santa Barbara, California 93117, USA
| | - T C White
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - D Sank
- Google Inc., Santa Barbara, California 93117, USA
| | - J Y Mutus
- Google Inc., Santa Barbara, California 93117, USA
| | - B Campbell
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - Yu Chen
- Google Inc., Santa Barbara, California 93117, USA
| | - Z Chen
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - B Chiaro
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - A Dunsworth
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - I-C Hoi
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - C Neill
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - P J J O'Malley
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - C Quintana
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - P Roushan
- Google Inc., Santa Barbara, California 93117, USA
| | - A Vainsencher
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - J Wenner
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - E Solano
- 1] Department of Physical Chemistry, University of the Basque Country UPV/EHU, Apartado 644, Bilbao E-48080, Spain. [2] IKERBASQUE, Basque Foundation for Science, Maria Diaz de Haro 3, Bilbao 48013, Spain
| | - John M Martinis
- 1] Google Inc., Santa Barbara, California 93117, USA. [2] Department of Physics, University of California, Santa Barbara, California 93106, USA
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5
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Kelly J, Barends R, Fowler AG, Megrant A, Jeffrey E, White TC, Sank D, Mutus JY, Campbell B, Chen Y, Chen Z, Chiaro B, Dunsworth A, Hoi IC, Neill C, O'Malley PJJ, Quintana C, Roushan P, Vainsencher A, Wenner J, Cleland AN, Martinis JM. State preservation by repetitive error detection in a superconducting quantum circuit. Nature 2015; 519:66-9. [PMID: 25739628 DOI: 10.1038/nature14270] [Citation(s) in RCA: 130] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Accepted: 01/27/2015] [Indexed: 12/19/2022]
Abstract
Quantum computing becomes viable when a quantum state can be protected from environment-induced error. If quantum bits (qubits) are sufficiently reliable, errors are sparse and quantum error correction (QEC) is capable of identifying and correcting them. Adding more qubits improves the preservation of states by guaranteeing that increasingly larger clusters of errors will not cause logical failure-a key requirement for large-scale systems. Using QEC to extend the qubit lifetime remains one of the outstanding experimental challenges in quantum computing. Here we report the protection of classical states from environmental bit-flip errors and demonstrate the suppression of these errors with increasing system size. We use a linear array of nine qubits, which is a natural step towards the two-dimensional surface code QEC scheme, and track errors as they occur by repeatedly performing projective quantum non-demolition parity measurements. Relative to a single physical qubit, we reduce the failure rate in retrieving an input state by a factor of 2.7 when using five of our nine qubits and by a factor of 8.5 when using all nine qubits after eight cycles. Additionally, we tomographically verify preservation of the non-classical Greenberger-Horne-Zeilinger state. The successful suppression of environment-induced errors will motivate further research into the many challenges associated with building a large-scale superconducting quantum computer.
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Affiliation(s)
- J Kelly
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - R Barends
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - A G Fowler
- 1] Department of Physics, University of California, Santa Barbara, California 93106, USA [2] Centre for Quantum Computation and Communication Technology, School of Physics, The University of Melbourne, Victoria 3010, Australia
| | - A Megrant
- 1] Department of Physics, University of California, Santa Barbara, California 93106, USA [2] Department of Materials, University of California, Santa Barbara, California 93106, USA
| | - E Jeffrey
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - T C White
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - D Sank
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - J Y Mutus
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - B Campbell
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - Yu Chen
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - Z Chen
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - B Chiaro
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - A Dunsworth
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - I-C Hoi
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - C Neill
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - P J J O'Malley
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - C Quintana
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - P Roushan
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - A Vainsencher
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - J Wenner
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - A N Cleland
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - John M Martinis
- Department of Physics, University of California, Santa Barbara, California 93106, USA
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6
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Chen Y, Neill C, Roushan P, Leung N, Fang M, Barends R, Kelly J, Campbell B, Chen Z, Chiaro B, Dunsworth A, Jeffrey E, Megrant A, Mutus JY, O'Malley PJJ, Quintana CM, Sank D, Vainsencher A, Wenner J, White TC, Geller MR, Cleland AN, Martinis JM. Qubit Architecture with High Coherence and Fast Tunable Coupling. Phys Rev Lett 2014; 113:220502. [PMID: 25494061 DOI: 10.1103/physrevlett.113.220502] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Indexed: 06/04/2023]
Abstract
We introduce a superconducting qubit architecture that combines high-coherence qubits and tunable qubit-qubit coupling. With the ability to set the coupling to zero, we demonstrate that this architecture is protected from the frequency crowding problems that arise from fixed coupling. More importantly, the coupling can be tuned dynamically with nanosecond resolution, making this architecture a versatile platform with applications ranging from quantum logic gates to quantum simulation. We illustrate the advantages of dynamical coupling by implementing a novel adiabatic controlled-z gate, with a speed approaching that of single-qubit gates. Integrating coherence and scalable control, the introduced qubit architecture provides a promising path towards large-scale quantum computation and simulation.
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Affiliation(s)
- Yu Chen
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - C Neill
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - P Roushan
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - N Leung
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - M Fang
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - R Barends
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - J Kelly
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - B Campbell
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - Z Chen
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - B Chiaro
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - A Dunsworth
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - E Jeffrey
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - A Megrant
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA and Department of Materials, University of California, Santa Barbara, California 93106-5050, USA
| | - J Y Mutus
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - P J J O'Malley
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - C M Quintana
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - D Sank
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - A Vainsencher
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - J Wenner
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - T C White
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - Michael R Geller
- Department of Physics and Astronomy, University of Georgia, Athens, Georgia 30602, USA
| | - A N Cleland
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - John M Martinis
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
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7
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Jeffrey E, Sank D, Mutus JY, White TC, Kelly J, Barends R, Chen Y, Chen Z, Chiaro B, Dunsworth A, Megrant A, O'Malley PJJ, Neill C, Roushan P, Vainsencher A, Wenner J, Cleland AN, Martinis JM. Fast accurate state measurement with superconducting qubits. Phys Rev Lett 2014; 112:190504. [PMID: 24877923 DOI: 10.1103/physrevlett.112.190504] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Indexed: 06/03/2023]
Abstract
Faster and more accurate state measurement is required for progress in superconducting qubit experiments with greater numbers of qubits and advanced techniques such as feedback. We have designed a multiplexed measurement system with a bandpass filter that allows fast measurement without increasing environmental damping of the qubits. We use this to demonstrate simultaneous measurement of four qubits on a single superconducting integrated circuit, the fastest of which can be measured to 99.8% accuracy in 140 ns. This accuracy and speed is suitable for advanced multiqubit experiments including surface-code error correction.
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Affiliation(s)
- Evan Jeffrey
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - Daniel Sank
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - J Y Mutus
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - T C White
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - J Kelly
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - R Barends
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - Y Chen
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - Z Chen
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - B Chiaro
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - A Dunsworth
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - A Megrant
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - P J J O'Malley
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - C Neill
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - P Roushan
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - A Vainsencher
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - J Wenner
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - A N Cleland
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
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Jeffrey E, Sank D, Mutus JY, White TC, Kelly J, Barends R, Chen Y, Chen Z, Chiaro B, Dunsworth A, Megrant A, O'Malley PJJ, Neill C, Roushan P, Vainsencher A, Wenner J, Cleland AN, Martinis JM. Fast accurate state measurement with superconducting qubits. Phys Rev Lett 2014; 112:190504. [PMID: 24877923 DOI: 10.1103/physrevlett.112.210501] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Indexed: 05/23/2023]
Abstract
Faster and more accurate state measurement is required for progress in superconducting qubit experiments with greater numbers of qubits and advanced techniques such as feedback. We have designed a multiplexed measurement system with a bandpass filter that allows fast measurement without increasing environmental damping of the qubits. We use this to demonstrate simultaneous measurement of four qubits on a single superconducting integrated circuit, the fastest of which can be measured to 99.8% accuracy in 140 ns. This accuracy and speed is suitable for advanced multiqubit experiments including surface-code error correction.
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Affiliation(s)
- Evan Jeffrey
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - Daniel Sank
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - J Y Mutus
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - T C White
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - J Kelly
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - R Barends
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - Y Chen
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - Z Chen
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - B Chiaro
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - A Dunsworth
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - A Megrant
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - P J J O'Malley
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - C Neill
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - P Roushan
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - A Vainsencher
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - J Wenner
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
| | - A N Cleland
- Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
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