Article
Multidisciplinary Sciences
Anastasiya A. Pishchimova, Nikita S. Smirnov, Daria A. Ezenkova, Elizaveta A. Krivko, Evgeniy V. Zikiy, Dmitry O. Moskalev, Anton I. Ivanov, Nikita D. Korshakov, Ilya A. Rodionov
Summary: Josephson superconducting qubits and parametric amplifiers have made significant progress in recent years. As these devices become more complex, the reproducibility of their electrical properties across a chip becomes increasingly important. This study focuses on minimizing the variation of the critical current in Josephson junctions, which is the essential electrical parameter in a chip. By optimizing the fabrication process, the resistance variation across different chip areas is reduced, ensuring high reproducibility.
SCIENTIFIC REPORTS
(2023)
Article
Physics, Applied
Junwen Zeng, Lei Chen, Xianghai Zhong, Yue Wang, Yinping Pan, Denghui Zhang, Shujie Yu, Ling Wu, Lu Zhang, Wei Peng, Zhen Wang
Summary: This research presents a superconducting memory cell that utilizes a superconducting-magnetic pi junction. The cell exhibits flux quantum hysteresis centered around the zero-bias current. Furthermore, a fabrication process combining superconductor-ferromagnet-superconductor (SFS) junctions with superconductor-normal metal-superconductor (SNS) junctions is developed, successfully achieving the formation of the pi junction.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2022)
Article
Physics, Multidisciplinary
Zheng-Yin Zhao, Run-Ying Yan, Zhi-Bo Feng
Summary: This study proposes an efficient scheme for performing quantum gates based on shortcuts in circuit quantum electrodynamics, enabling the implementation of single-qubit NOT gate, phase gate, and one-step SWAP gate, with microwave field adjustments. The approach exhibits high fidelity in experiments and offers a promising route for fast and robust quantum computation with superconducting circuits.
Article
Computer Science, Information Systems
Wen-Sen Lu, Konstantin Kalashnikov, Plamen Kamenov, Thomas J. DiNapoli, Michael E. Gershenson
Summary: This study reports a systematic study of incoherent phase slips (IPS) in low-Josephson energy Josephson junctions (JJs) at milli-Kelvin temperatures. The results show that with a decrease in Josephson energy, the critical current in JJs is suppressed and the zero-bias resistance shows a rapid growth due to IPS. These findings suggest that IPS-induced dissipation may limit the performance of qubits based on low-Josephson energy junctions.
Article
Engineering, Electrical & Electronic
Yongliang Wang
Summary: This article presents an electromagnetic-flux-distribution model to unify the analyses of superconducting and non-superconducting circuits. The model uses electric and magnetic fluxes as variables to unify the definitions of circuit elements and circuit laws, and derives general circuit equations to describe the dynamics and duality principles of the circuits. This method is demonstrated in the analyses of a Josephson junction circuit and its dual QPS junction circuit.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2022)
Article
Physics, Multidisciplinary
Benzheng Yuan, Weilong Wang, Fudong Liu, Haoran He, Zheng Shan
Summary: This paper compares the LOM and EPR quantification methods in the design of superconducting quantum chips and summarizes the advantages and disadvantages of these two methods. The results show that the LOM method has more parameter outputs and more accurate qubit frequency calculation, providing reference significance for the design of superconducting quantum chips.
Article
Multidisciplinary Sciences
Marina Bastrakova, Anastasiya Gorchavkina, Andrey Schegolev, Nikolay Klenov, Igor Soloviev, Arkady Satanin, Maxim Tereshonok
Summary: The study found that the dynamic processes in an S-C neuron can implement the transfer characteristic mode of the sigmoid activation function. The dynamic characteristics of the neuron are influenced by inertia, dissipation, and temperature.
Review
Quantum Science & Technology
Atharv Joshi, Kyungjoo Noh, Yvonne Y. Gao
Summary: The unique features of quantum theory offer a powerful new paradigm for information processing, but translating these into useful algorithms and applications requires complex quantum systems with low error rates. cQED provides a promising hardware platform for robust quantum devices, particularly in utilizing bosonic encodings with multi-photon states in superconducting cavities.
QUANTUM SCIENCE AND TECHNOLOGY
(2021)
Article
Physics, Applied
A. Osman, J. Simon, A. Bengtsson, S. Kosen, P. Krantz, D. P. Lozano, M. Scigliuzzo, P. Delsing, Jonas Bylander, A. Fadavi Roudsari
Summary: A simplified fabrication technique for Josephson junctions has been introduced, which demonstrates superconducting Xmon qubits with high coherence times. By integrating a patch in the junction fabrication process, the manufacturing bottleneck is reduced, providing higher predictability for qubit performance and allowing for scalability in quantum computing. The study also shows that most of the frequency variation in the junctions is attributed to junction-area fluctuations, emphasizing the importance of consistency in fabrication for quantum computer applications.
APPLIED PHYSICS LETTERS
(2021)
Article
Physics, Applied
Quentin Herr, Trent Josephsen, Anna Herr
Summary: Superconducting digital pulse-conserving logic and Josephson static random access memory (JSRAM) memory together enable scalable circuits with 100x energy efficiency beyond leading-node CMOS. The circuit designs support high throughput and low latency, achieved through advanced fabrication stack and high-critical-current-density Josephson junctions. Pulse-conserving logic produces one output for each input, including logical or3, majority3, and and3. JSRAM memory achieves high throughput using single-flux-quantum signals, with a unit cell footprint of 2 mu m(2) and a propagation latency of 1 ps. Projected densities of JSRAM and computational density of pulse-conserving logic are competitive with leading node CMOS.
APPLIED PHYSICS LETTERS
(2023)
Article
Nanoscience & Nanotechnology
Joydip Sarkar, Kishor Salunkhe, Supriya Mandal, Subhamoy Ghatak, Alisha H. Marchawala, Ipsita Das, Kenji Watanabe, Takashi Taniguchi, R. Vijay, Mandar M. Deshmukh
Summary: Josephson junctions (JJs) and their tunable properties are crucial for superconducting qubits and amplifiers. This study demonstrates a quantum-noise-limited Josephson parametric amplifier (JPA) using a graphene Josephson junction (JJ) with linear resonance gate tunability. The gate-tunable JPA exhibits high amplification performance and operates in the quantum-limited noise regime, making it an attractive option for sensitive signal processing.
NATURE NANOTECHNOLOGY
(2022)
Article
Physics, Applied
N. G. Pugach, D. M. Heim, D. Seleznev, A. Chernov, D. Menzel
Summary: We propose a superconducting spin valve based on a Josephson junction with B20-family magnetic metal as a barrier material. By reorienting the magnetization of the spiral magnet, the states of this device can be switched, which strongly influences the critical Josephson current. Compared to previous superconducting spin valves, our device is easier to fabricate and control, has a stable ground state, and is compatible with low-T Josephson electronics.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(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
M. S. Blok, V. V. Ramasesh, T. Schuster, K. O'Brien, J. M. Kreikebaum, D. Dahlen, A. Morvan, B. Yoshida, N. Y. Yao, I Siddiqi
Summary: This research demonstrates scrambling operations on three-level quantum systems (qutrits) and applies them to quantum teleportation protocols. Despite imperfections and decoherence in the experiment, the study verifies the presence of scrambling. This indicates that quantum technology encoding information in higher-dimensional systems can achieve more resource-efficient encoding.
Article
Physics, Applied
I. I. Soloviev, S. Bakurskiy, V. Ruzhickiy, N. Klenov, M. Yu Kupriyanov, A. A. Golubov, O. Skryabina, V. S. Stolyarov
Summary: The work provides an overview of various options for Josephson junctions for nanoscale digital superconducting technology, highlighting the potential of the SN-N-NS junction with variable thickness bridge geometry. Theoretical analysis and fabrication processes are discussed, showing the feasibility of achieving high IcRN product values and scaling down the junction area to semiconductor transistor levels.
PHYSICAL REVIEW APPLIED
(2021)
Article
Multidisciplinary Sciences
Jeremy B. Clark, Florent Lecocq, Raymond W. Simmonds, Jose Aumentado, John D. Teufel
Article
Instruments & Instrumentation
T. Menke, P. S. Burns, A. P. Higginbotham, N. S. Kampel, R. W. Peterson, K. Cicak, R. W. Simmonds, C. A. Regal, K. W. Lehnert
REVIEW OF SCIENTIFIC INSTRUMENTS
(2017)
Article
Physics, Multidisciplinary
G. A. Peterson, F. Lecocq, K. Cicak, R. W. Simmonds, J. Aumentado, J. D. Teufel
Article
Physics, Multidisciplinary
N. S. Kampel, R. W. Peterson, R. Fischer, P. -L. Yu, K. Cicak, R. W. Simmonds, K. W. Lehnert, C. A. Regal
Article
Physics, Applied
F. Lecocq, L. Ranzani, G. A. Peterson, K. Cicak, R. W. Simmonds, J. D. Teufel, J. Aumentado
PHYSICAL REVIEW APPLIED
(2017)
Article
Multidisciplinary Sciences
Andrew D. King, Juan Carrasquilla, Jack Raymond, Isil Ozfidan, Evgeny Andriyash, Andrew Berkley, Mauricio Reis, Trevor Lanting, Richard Harris, Fabio Altomare, Kelly Boothby, Paul I. Bunyk, Colin Enderud, Alexandre Frechette, Emile Hoskinson, Nicolas Ladizinsky, Travis Oh, Gabriel Poulin-Lamarre, Christopher Rich, Yuki Sato, Anatoly Yu. Smirnov, Loren J. Swenson, Mark H. Volkmann, Jed Whittaker, Jason Yao, Eric Ladizinsky, Mark W. Johnson, Jeremy Hilton, Mohammad H. Amin
Article
Multidisciplinary Sciences
R. Harris, Y. Sato, A. J. Berkley, M. Reis, F. Altomare, M. H. Amin, K. Boothby, P. Bunyk, C. Deng, C. Enderud, S. Huang, E. Hoskinson, M. W. Johnson, E. Ladizinsky, N. Ladizinsky, T. Lanting, R. Li, T. Medina, R. Molavi, R. Neufeld, T. Oh, I. Pavlov, I. Perminov, G. Poulin-Lamarre, C. Rich, A. Smirnov, L. Swenson, N. Tsai, M. Volkmann, J. Whittaker, J. Yao
Article
Physics, Multidisciplinary
G. A. Peterson, S. Kotler, F. Lecocq, K. Cicak, X. Y. Jin, R. W. Simmonds, J. Aumentado, J. D. Teufel
PHYSICAL REVIEW LETTERS
(2019)
Article
Physics, Applied
F. Lecocq, L. Ranzani, G. A. Peterson, K. Cicak, A. Metelmann, S. Kotler, R. W. Simmonds, J. D. Teufel, J. Aumentado
PHYSICAL REVIEW APPLIED
(2020)
Article
Physics, Multidisciplinary
F. Lecocq, L. Ranzani, G. A. Peterson, K. Cicak, X. Y. Jin, R. W. Simmonds, J. D. Teufel, J. Aumentado
Summary: Quantum measurement perturbs the state of a quantum object, with the measurement responsible for all dephasing ideally. Imperfections in measurement apparatus can limit or corrupt the flow of information needed for quantum feedback protocols. Efficient measurement of a superconducting qubit using a nonreciprocal parametric amplifier has been demonstrated, with potential applications in improving fidelity of strong projective measurement and exploring weak measurements for quantum feedback protocols.
PHYSICAL REVIEW LETTERS
(2021)
Article
Multidisciplinary Sciences
Shlomi Kotler, Gabriel A. Peterson, Ezad Shojaee, Florent Lecocq, Katarina Cicak, Alex Kwiatkowski, Shawn Geller, Scott Glancy, Emanuel Knill, Raymond W. Simmonds, Jose Aumentado, John D. Teufel
Summary: In this study, two mechanical drumheads with masses of 70 picograms were deterministically entangled using pulsed electromechanics. Quantum state tomography was performed through nearly quantum-limited measurements, allowing for the direct observation of entanglement. These entangled macroscopic systems are expected to be used in fundamental tests of quantum mechanics, enable sensing beyond the standard quantum limit, and function as long-lived nodes in future quantum networks.
Article
Physics, Applied
A. Goswami, A. P. McFadden, T. Zhao, H. Inbar, J. T. Dong, R. Zhao, C. R. H. McRae, R. W. Simmonds, C. J. Palmstrom, D. P. Pappas
Summary: A merged-element transmon (MET) device based on silicon fins is proposed, and the first steps to form such a FinMET are demonstrated. This new application of fin technology utilizes the anisotropic etch of Si(111) to define flat and high aspect ratio Si tunnel barriers with superconductor contacts. By using low-loss intrinsic float-zone Si as the barrier material, the FinMET is expected to overcome problems with standard transmons and allow scalable fabrication.
APPLIED PHYSICS LETTERS
(2022)
Article
Physics, Applied
Z. Xiao, E. Doucet, T. Noh, L. Ranzani, R. W. Simmonds, L. C. G. Govia, A. Kamal
Summary: We present a systematic method to implement perturbative Hamiltonian diagonalization using the time-dependent Schrieffer-Wolff transformation. Applying this method to strong parametric interactions, we show that the full Rabi model physics is crucial for describing the dressed spectrum even in the dispersive regime. Our results reveal several qualitatively different outcomes, including the realization of large energy level shifts that can be tuned in magnitude and sign with the frequency and amplitude of the pump mediating the parametric interaction. The framework developed here expands the capabilities for controlling and reading out strongly interacting quantum systems by highlighting the rich physics accessible with time-dependent interactions.
PHYSICAL REVIEW APPLIED
(2022)
Article
Materials Science, Multidisciplinary
Alexander M. Whiticar, Anatoly Y. Smirnov, Trevor Lanting, Jed Whittaker, Fabio Altomare, Teresa Medina, Rahul Deshpande, Sara Ejtemaee, Emile Hoskinson, Michael Babcock, Mohammad H. Amin
Summary: This paper reports on measurements of flux and charge noise in an rf-SQUID flux qubit using macroscopic resonant tunneling. The authors measure rates of incoherent tunneling between energy states in different wells and develop a theoretical model to extract information about flux and charge noise. The model agrees well with experimental data and provides parameters characterizing the noise sources.
Article
Optics
Shlomi Kotler, Raymond W. Simmonds, Dietrich Leibfried, David J. Wineland
