Article
Physics, Multidisciplinary
J. Stehlik, D. M. Zajac, D. L. Underwood, T. Phung, J. Blair, S. Carnevale, D. Klaus, G. A. Keefe, A. Carniol, M. Kumph, Matthias Steffen, O. E. Dial
Summary: The article introduces a modified tunable bus architecture suitable for fixed-frequency qubits, achieving high-fidelity 2-qubit operations. Experimental results demonstrate a maximum gate fidelity of 99.85% with good calibration stability over one day.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Tim Menke, William P. Banner, Thomas R. Bergamaschi, Agustin Di Paolo, Antti Vepsalainen, Steven J. Weber, Roni Winik, Alexander Melville, Bethany M. Niedzielski, Danna Rosenberg, Kyle Serniak, Mollie E. Schwartz, Jonilyn L. Yoder, Alan Aspuru-Guzik, Simon Gustavsson, Jeffrey A. Grover, Cyrus F. Hirjibehedin, Andrew J. Kerman, William D. Oliver
Summary: This study presents a superconducting circuit architecture that enables two-local and three-local interactions between three flux qubits through a designed coupling module. The system Hamiltonian is estimated using multiqubit pulse sequences implementing Ramsey-type interferometry. The three-local interaction can be coherently tuned over several MHz via the coupler flux biases and can also be turned off. This research has significant applications in quantum annealing, analog quantum simulation, and gate-model quantum computation.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
Yufeng Ye, Kaidong Peng, Mahdi Naghiloo, Gregory Cunningham, Kevin P. O'Brien
Summary: The study introduces the use of quarton to achieve pure nonlinear coupling between qubits, enabling ultrastrong gigahertz-level cross-Kerr coupling and cancelling out the self-Kerr nonlinearity of qubits. This makes the qubits linearized into resonators and ideal for applications like single microwave photon detection, ultrafast two-qubit gates, and readout.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Tong Liu, Bao-Qing Guo, Yan-Hui Zhou, Jun-Long Zhao, Yu-Liang Fang, Qi-Cheng Wu, Chui-Ping Yang
Summary: This article proposes a method for transferring entangled states between superconducting qubits and microwave-field qubits, using multiple superconducting qutrits and microwave cavities. The method allows for deterministic transfer and reduces decoherence effects.
FRONTIERS OF PHYSICS
(2022)
Article
Optics
Shaojie Yuan, Chuanpu Liu, Jilei Chen, Song Liu, Jin Lan, Haiming Yu, Jiansheng Wu, Fei Yan, Jiang Xiao, Liang Jiang, Dapeng Yu
Summary: Recent progress in quantum computing and simulation based on superconducting qubits has entered the noisy intermediate-scale quantum (NISQ) era. This article proposes a hybrid system consisting of superconducting qubits and a yttrium iron garnet (YIG) system as an alternative way to achieve coupling for quantum information processing. Numerical simulations demonstrate coherent transfer of quantum information between the flux qubit and the standing spin waves in YIG thin films.
Article
Multidisciplinary Sciences
Yu Zhou, Zhenxing Zhang, Zelong Yin, Sainan Huai, Xiu Gu, Xiong Xu, Jonathan Allcock, Fuming Liu, Guanglei Xi, Qiaonian Yu, Hualiang Zhang, Mengyu Zhang, Hekang Li, Xiaohui Song, Zhan Wang, Dongning Zheng, Shuoming An, Yarui Zheng, Shengyu Zhang
Summary: The study presents a fast and high-fidelity reset scheme for quantum qubits, achieved by modulating the flux through the qubit to swap with its readout resonator within 34 ns. This approach can effectively deplete the second excited state, has negligible effects on neighboring qubits, and offers a way to entangle the qubit with a single photon for quantum communication applications.
NATURE COMMUNICATIONS
(2021)
Article
Multidisciplinary Sciences
Elena S. Redchenko, Alexander V. Poshakinskiy, Riya Sett, Martin Zemlicka, Alexander N. Poddubny, Johannes M. Fink
Summary: The two frequency-modulated superconducting qubits act as a switchable mirror for microwave photons, providing on-demand tunable directional scattering. This ability is crucial for various on-chip applications, such as integrated photonics, quantum information processing, and nonlinear optics. By changing the relative phase between the modulation tones, unidirectional forward or backward photon scattering can be realized. This in-situ switchable mirror represents a versatile tool for intra- and inter-chip microwave photonic processors.
NATURE COMMUNICATIONS
(2023)
Article
Physics, Applied
Peng Zhao, Yingshan Zhang, Guangming Xue, Yirong Jin, Haifeng Yu
Summary: This research proposes a conceptual design of a modular quantum device, which achieves qubit coupling between modules through a tunable longer-range coupling scheme. The experimental results show that sub-100-ns two-qubit gates can be achieved for qubits housed in nearby modules that are spatially separated by more than two centimeters. This modular architecture and coupling scheme provide a promising foundation for large-scale quantum information processing with superconducting qubits.
APPLIED PHYSICS LETTERS
(2022)
Article
Quantum Science & Technology
J. H. Bejanin, C. T. Earnest, Y. R. Sanders, M. Mariantoni
Summary: This paper demonstrates a method to efficiently learn the parameters of resonant interactions in quantum computers, utilizing offline data collection and online Bayesian learning algorithms to significantly reduce calibration time. This technique has the potential to improve the performance of current medium-scale superconducting quantum computers and scale up to larger systems, making it accessible to different physical implementations of quantum computing architectures.
Article
Chemistry, Multidisciplinary
Mun-Dae Kim
Summary: This study investigates the galvanic coupling schemes of superconducting flux qubits and finds that the inductive coupling strength needs to be exactly included to satisfy the criteria of fault-tolerant quantum computing.
APPLIED SCIENCES-BASEL
(2021)
Article
Physics, Applied
Martin Sandberg, Vivekananda P. Adiga, Markus Brink, Cihan Kurter, Conal Murray, Marinus Hopstaken, John Bruley, Jason S. Orcutt, Hanhee Paik
Summary: Silicon-germanium (SiGe) is a versatile material with applications in superconducting quantum computing. By fabricating transmon quantum bits on SiGe layers and studying microwave loss properties at cryogenic temperatures, we achieved high quality factor Q values, confirming compatibility with state-of-the-art superconducting quantum circuits.
APPLIED PHYSICS LETTERS
(2021)
Article
Quantum Science & Technology
Nicholas Materise, Matthieu C. Dartiailh, William M. Strickland, Javad Shabani, Eliot Kapit
Summary: The adoption of fast, parametric coupling elements has improved the performance of superconducting qubits, leading to recent demonstrations of quantum advantage in randomized sampling problems. The development of low loss, high contrast couplers is crucial for scaling up these systems. This study presents a blueprint for a gate-tunable coupler realized with a two-dimensional electron gas in an InAs/InGaAs heterostructure, showing promising results in terms of on/off ratio and dielectric-limited loss.
QUANTUM SCIENCE AND TECHNOLOGY
(2023)
Article
Physics, Applied
T. Chang, T. Cohen, I. Holzman, G. Catelani, M. Stern
Summary: In this study, a series of tunable flux qubits coupled to a coplanar waveguide resonator on a sapphire substrate were investigated. Each qubit consists of an asymmetric superconducting quantum interference device that acts as a tunable Josephson junction controlled by an external magnetic field. The tunability of the qubits is typically +/- 3.5 GHz around their central gap frequency. The relaxation times are limited by dielectric losses in the substrate and can reach T1 of approximately 8 μs. The echo dephasing times are limited by flux noise even at optimal points and reach T2E of approximately 4 μs, almost an order of magnitude longer than the state of the art.
PHYSICAL REVIEW APPLIED
(2023)
Article
Physics, Applied
Ruixia Wang, Peng Zhao, Yirong Jin, Haifeng Yu
Summary: This article proposes an error mitigation scheme to address the microwave crosstalk issue in single-qubit gates of superconducting quantum processors. By controlling detuning, decomposing gates, and optimizing parameters, the error can be constrained and gate fidelity can be improved.
APPLIED PHYSICS LETTERS
(2022)
Article
Physics, Applied
A. D. K. Finck, S. Carnevale, D. Klaus, C. Scerbo, J. Blair, T. G. McConkey, C. Kurter, A. Carniol, G. Keefe, M. Kumph, O. E. Dial
Summary: The study experimentally demonstrates a superconducting architecture using qubits composed of two capacitively shunted Josephson junctions connected in series to address the issue of fixed-frequency qubits suffering from always-on interactions that inhibit independent control. These new two-junction qubits, historically known as tunable coupling qubits (TCQs), support two modes with distinct frequencies and spatial symmetries, allowing for greatly suppressed crosstalk between data modes by selectively coupling only one type of mode.
PHYSICAL REVIEW APPLIED
(2021)
Article
Physics, Multidisciplinary
A. Morvan, V. V. Ramasesh, M. S. Blok, J. M. Kreikebaum, K. O'Brien, L. Chen, B. K. Mitchell, R. K. Naik, D. Santiago, I Siddiqi
Summary: The study demonstrates extensions of industry standard randomized benchmarking (RB) protocols for ternary quantum logic, allowing for the evaluation of performance. Testing using a superconducting five-level processor revealed the average infidelity of a single-qutrit process, characterizing relevant gates through interleaved RB, and evaluating a two-qutrit gate using cycle benchmarking.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Akel Hashim, Ravi K. Naik, Alexis Morvan, Jean-Loup Ville, Bradley Mitchell, John Mark Kreikebaum, Marc Davis, Ethan Smith, Costin Iancu, Kevin P. O'Brien, Ian Hincks, Joel J. Wallman, Joseph Emerson, Irfan Siddiqi
Summary: The successful implementation of algorithms on quantum processors requires accurate control of quantum bits, but coherent errors can severely limit performance. Randomized compiling can convert coherent errors into stochastic noise, reducing unpredictable errors and enabling accurate prediction of algorithmic performance. This approach demonstrates significant performance gains and accurately predicts algorithm performance on modern-day noisy quantum processors, paving the way for scalable quantum computing.
Correction
Physics, Multidisciplinary
Yosep Kim, Alexis Morvan, Long B. Nguyen, Ravi K. Naik, Christian Junger, Larry Chen, John Mark Kreikebaum, David I. Santiago, Irfan Siddiqi
Article
Physics, Multidisciplinary
Yosep Kim, Alexis Morvan, Long B. Nguyen, Ravi K. Naik, Christian Junger, Larry Chen, John Mark Kreikebaum, David Santiago, Irfan Siddiqi
Summary: The development of noisy intermediate-scale quantum devices has brought about a wider range of executable high-fidelity single- and two-qubit gates. In this study, a high-fidelity iToffoli gate based on two-qubit interactions is demonstrated using fixed-frequency superconducting qubits. The gate implementation process achieves a fidelity of up to 98.26(2)%. Numerical simulations also show that the gate scheme used can produce more efficient three-qubit gates than the traditional Toffoli and iToffoli gates. This work not only introduces a high-fidelity iToffoli gate to current superconducting quantum processors, but also paves the way for developing multi-qubit gates based on two-qubit interactions.
Article
Physics, Multidisciplinary
Srivatsan Chakram, Kevin He, Akash Dixit, Andrew E. Oriani, Ravi K. Naik, Nelson Leung, Hyeokshin Kwon, Wen-Long Ma, Liang Jiang, David Schuster
Summary: Interactions play a crucial role in generating correlated quantum many-body states and are important for various physics phenomena. A new scheme has been implemented to create high-order interactions between photons stored in multiple electromagnetic modes of a microwave cavity. This method allows for the preparation of single-mode Fock states and multimode W states.
Article
Physics, Multidisciplinary
G. Koolstra, N. Stevenson, S. Barzili, L. Burns, K. Siva, S. Greenfield, W. Livingston, A. Hashim, R. K. Naik, J. M. Kreikebaum, K. P. O'Brien, D. Santiago, J. Dressel, I Siddiqi
Summary: In this study, we propose an alternative method to accurately track the trajectories of rapidly driven superconducting qubits using a long short-term memory (LSTM) artificial neural network with minimal prior information. The LSTM produces trajectories that include qubit-readout resonator correlations and can accurately reconstruct the evolution of an unknown drive.
Article
Physics, Applied
Hyunseong Kim, Christian Junger, Alexis Morvan, Edward S. Barnard, William P. Livingston, M. Virginia P. Altoe, Yosep Kim, Chengyu Song, Larry Chen, John Mark Kreikebaum, D. Frank Ogletree, David I. Santiago, Irfan Siddiqi
Summary: As superconducting quantum processors become more complex, it is necessary to develop techniques to overcome frequency crowding constraints. Laser-annealing, a recently developed method, offers an effective post-fabrication approach to adjust the frequency of superconducting qubits. This study presents an automated laser-annealing apparatus based on conventional microscopy components and demonstrates the preservation of highly coherent transmons. The researchers also investigate the change in defect features, particularly two-level system defects, after laser-annealing using noise spectroscopy.
APPLIED PHYSICS LETTERS
(2022)
Article
Multidisciplinary Sciences
A. Morvan, T. I. Andersen, X. Mi, C. Neill, A. Petukhov, K. Kechedzhi, D. A. Abanin, A. Michailidis, R. Acharya, F. Arute, K. Arya, A. Asfaw, J. Atalaya, J. C. Bardin, J. Basso, A. Bengtsson, G. Bortoli, A. Bourassa, J. Bovaird, L. Brill, M. Broughton, B. B. Buckley, D. A. Buell, T. Burger, B. Burkett, N. Bushnell, Z. Chen, B. Chiaro, R. Collins, P. Conner, W. Courtney, A. L. Crook, B. Curtin, D. M. Debroy, A. Del Toro Barba, S. Demura, A. Dunsworth, D. Eppens, C. Erickson, L. Faoro, E. Farhi, R. Fatemi, L. Flores Burgos, E. Forati, A. G. Fowler, B. Foxen, W. Giang, C. Gidney, D. Gilboa, M. Giustina, A. Grajales Dau, J. A. Gross, S. Habegger, M. C. Hamilton, M. P. Harrigan, S. D. Harrington, M. Hoffmann, S. Hong, T. Huang, A. Huff, W. J. Huggins, S. V. Isakov, J. Iveland, E. Jeffrey, Z. Jiang, C. Jones, P. Juhas, D. Kafri, T. Khattar, M. Khezri, M. Kieferova, S. Kim, A. Y. Kitaev, P. V. Klimov, A. R. Klots, A. N. Korotkov, F. Kostritsa, J. M. Kreikebaum, D. Landhuis, P. Laptev, K. -m. Lau, L. Laws, J. Lee, K. W. Lee, B. J. Lester, A. T. Lill, W. Liu, A. Locharla, F. Malone, O. Martin, J. R. McClean, M. McEwen, B. Meurer Costa, K. C. Miao, M. Mohseni, S. Montazeri, E. Mount, W. Mruczkiewicz, O. Naaman, M. Neeley, A. Nersisyan, M. Newman, A. Nguyen, M. Nguyen, M. Y. Niu, T. E. O'Brien, R. Olenewa, A. Opremcak, R. Potter, C. Quintana, N. C. Rubin, N. Saei, D. Sank, K. Sankaragomathi, K. J. Satzinger, H. F. Schurkus, C. Schuster, M. J. Shearn, A. Shorter, V. Shvarts, J. Skruzny, W. C. Smith, D. Strain, G. Sterling, Y. Su, M. Szalay, A. Torres, G. Vidal, B. Villalonga, C. Vollgraff-Heidweiller, T. White, C. Xing, Z. Yao, P. Yeh, J. Yoo, A. Zalcman, Y. Zhang, N. Zhu, H. Neven, D. Bacon, J. Hilton, E. Lucero, R. Babbush, S. Boixo, A. Megrant, J. Kelly, Y. Chen, V. Smelyanskiy, I. Aleiner, L. B. Ioffe, P. Roushan
Summary: Systems of correlated particles present computational challenges when interactions become comparable to other energy scales, and our understanding of these systems fades as the particle number or interaction strength increases. This study provides experimental evidence for the existence and stability of bound states of interacting photons beyond the integrability limit, shedding light on the impact of integrability on bound states.
Article
Multidisciplinary Sciences
T. I. Andersen, Y. D. Lensky, K. Kechedzhi, I. K. Drozdov, A. Bengtsson, S. Hong, A. Morvan, X. Mi, A. Opremcak, R. Acharya, R. Allen, M. Ansmann, F. Arute, K. Arya, A. Asfaw, J. Atalaya, R. Babbush, D. Bacon, J. C. Bardin, G. Bortoli, A. Bourassa, J. Bovaird, L. Brill, M. Broughton, B. B. Buckley, D. A. Buell, T. Burger, B. Burkett, N. Bushnell, Z. Chen, B. Chiaro, D. Chik, C. Chou, J. Cogan, R. Collins, P. Conner, W. Courtney, A. L. Crook, B. Curtin, D. M. Debroy, A. Del Toro Barba, S. Demura, A. Dunsworth, D. Eppens, C. Erickson, L. Faoro, E. Farhi, R. Fatemi, V. S. Ferreira, L. F. Burgos, E. Forati, A. G. Fowler, B. Foxen, W. Giang, C. Gidney, D. Gilboa, M. Giustina, R. Gosula, A. G. Dau, J. A. Gross, S. Habegger, M. C. Hamilton, M. Hansen, M. P. Harrigan, S. D. Harrington, P. Heu, J. Hilton, M. R. Hoffmann, T. Huang, A. Huff, W. J. Huggins, L. B. Ioffe, S. V. Isakov, J. Iveland, E. Jeffrey, Z. Jiang, C. Jones, P. Juhas, D. Kafri, T. Khattar, M. Khezri, M. Kieferova, S. Kim, A. Kitaev, P. V. Klimov, A. R. Klots, A. N. Korotkov, F. Kostritsa, J. M. Kreikebaum, D. Landhuis, P. Laptev, K. -M. Lau, L. Laws, J. Lee, K. W. Lee, B. J. Lester, A. T. Lill, W. Liu, A. Locharla, E. Lucero, F. D. Malone, O. Martin, J. R. McClean, T. McCourt, M. McEwen, K. C. Miao, A. Mieszala, M. Mohseni, S. Montazeri, E. Mount, R. Movassagh, W. Mruczkiewicz, O. Naaman, M. Neeley, C. Neill, A. Nersisyan, M. Newman, J. H. Ng, A. Nguyen, M. Nguyen, M. Y. Niu, T. E. O'Brien, S. Omonije, A. Petukhov, R. Potter, L. P. Pryadko, C. Quintana, C. Rocque, N. C. Rubin, N. Saei, D. Sank, K. Sankaragomathi, K. J. Satzinger, H. F. Schurkus, C. Schuster, M. J. Shearn, A. Shorter, N. Shutty, V. Shvarts, J. Skruzny, W. C. Smith, R. Somma, G. Sterling, D. Strain, M. Szalay, A. Torres, G. Vidal, B. Villalonga, C. V. Heidweiller, T. White, B. W. K. Woo, C. Xing, Z. J. Yao, P. Yeh, J. Yoo, G. Young, A. Zalcman, Y. Zhang, N. Zhu, N. Zobrist, H. Neven, S. Boixo, A. Megrant, J. Kelly, Y. Chen, V. Smelyanskiy, E. -A. Kim, I. Aleiner, P. Roushan
Summary: Indistinguishability of particles is a fundamental principle in quantum mechanics. While braiding of Abelian anyons leaves the system unchanged, braiding of non-Abelian anyons can change the observables of the system without violating the principle of indistinguishability. Experimental observation of non-Abelian anyons' exchange statistics has remained elusive, but using quantum processors, it is now possible to manipulate and braid them, allowing for the verification of their fusion rules and statistics. This work provides insights into non-Abelian braiding and its potential application in fault-tolerant quantum computing with the inclusion of error correction.
Article
Quantum Science & Technology
Akel Hashim, Stefan Seritan, Timothy Proctor, Kenneth Rudinger, Noah Goss, Ravi K. Naik, John Mark Kreikebaum, David I. Santiago, Irfan Siddiqi
Summary: It is found that under randomized compiling (RC), the errors of quantum gates can be accurately described by a stochastic Pauli noise model without coherent errors, and spatially correlated coherent errors and non-Markovian errors are strongly suppressed. The average and worst-case error rates are equal for randomly compiled gates, and the maximum worst-case error for the gate set is measured to be 0.0197(3) using gate set tomography.
NPJ QUANTUM INFORMATION
(2023)
Article
Physics, Multidisciplinary
Alexis Morvan, Larry Chen, Jeffrey M. Larson, David Santiago, Irfan Siddiqi
Summary: This paper proposes a mixed-integer-programming-based optimization approach to determine qubit frequencies for maximizing the fabrication yield of quantum processors. By studying traditional qubit and qutrit architectures, as well as cross-resonance interaction processors, and comparing them to a differential ac-Stark shift based on entanglement gates, the approach greatly improves the fabrication yield and scalability of these devices.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Physics, Multidisciplinary
Alexis Morvan, Mathieu Fechant, Gianluca Aiello, Julien Gabelli, Jerome Esteve
Summary: This study designs various honeycomb lattices for microwave photons in the 4 to 8 GHz band using superconducting spiral resonators. The eigenmodes of these photonic lattices are imaged using a scanning laser technique, and their measured bands are in excellent agreement with theoretical models.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Quantum Science & Technology
Kenneth Rudinger, Craig W. Hogle, Ravi K. Naik, Akel Hashim, Daniel Lobser, David Santiago, Matthew D. Grace, Erik Nielsen, Timothy Proctor, Stefan Seritan, Susan M. Clark, Robin Blume-Kohout, Irfan Siddiqi, Kevin C. Young
Summary: Crosstalk is a major source of failure in multiqubit quantum information processors, which can be caused by various physical phenomena and introduce subtle correlations in device errors. Gate set tomography protocol can be used to identify and characterize crosstalk errors in quantum information processors.
