1
|
Saida D, Makise K, Hidaka M. Scalable interconnection using a superconducting flux qubit. Sci Rep 2024; 14:16447. [PMID: 39013922 PMCID: PMC11252359 DOI: 10.1038/s41598-024-65086-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Accepted: 06/17/2024] [Indexed: 07/18/2024] Open
Abstract
Superconducting quantum computers are rapidly reaching scales where bottlenecks to scaling arise from the practical aspects of the fabrication process. To improve quantum computer performance, implementation technology that guarantees the scalability of the number of qubits is essential. Increasing the degrees of freedom in routing by 2.5-dimensional implementation is important for realizing circuit scalability. We report an implementation technology to overcome the scaling bottlenecks using a reliable connection qubit with a demonstration of quantum annealing. The method comprises interconnection based on quantum annealing using a superconducting flux qubit, precise coupling status control, and flip-chip bonding. We perform experiments and simulations with a proof-of-concept demonstration of qubit coupling via interconnection using a flux qubit. The coupling status is strictly controllable by quantum annealing. A low-temperature flip-chip bonding technology is introduced for the 2.5-dimensional interconnection. The superconducting flux qubit, formed across two different chips via bumps, is demonstrated for the first time to show a state transition like that in a conventional qubit. The quantum annealing flux qubit and flip-chip bonding enable new interconnections between qubits. A perspective on the possibility of applying this technology to the connection between gate-type qubits is described.
Collapse
Affiliation(s)
- Daisuke Saida
- Fujitsu Limited, 1-1, Kamikodanaka 4-chome, Nakahara-ku, Kawasaki, Kanagawa, 211-8588, Japan.
- National Institute of Advanced Industrial Science and Technology, Ibaraki, Japan.
| | - Kazumasa Makise
- National Institute of Advanced Industrial Science and Technology, Ibaraki, Japan
- National Astronomical Observatory of Japan, Tokyo, Japan
| | - Mutsuo Hidaka
- National Institute of Advanced Industrial Science and Technology, Ibaraki, Japan
| |
Collapse
|
2
|
Pekola JP, Karimi B. Heat Bath in a Quantum Circuit. ENTROPY (BASEL, SWITZERLAND) 2024; 26:429. [PMID: 38785678 PMCID: PMC11120583 DOI: 10.3390/e26050429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2024] [Revised: 05/09/2024] [Accepted: 05/10/2024] [Indexed: 05/25/2024]
Abstract
We discuss the concept and realization of a heat bath in solid state quantum systems. We demonstrate that, unlike a true resistor, a finite one-dimensional Josephson junction array or analogously a transmission line with non-vanishing frequency spacing, commonly considered as a reservoir of a quantum circuit, does not strictly qualify as a Caldeira-Leggett type dissipative environment. We then consider a set of quantum two-level systems as a bath, which can be realized as a collection of qubits. We show that only a dense and wide distribution of energies of the two-level systems can secure long Poincare recurrence times characteristic of a proper heat bath. An alternative for this bath is a collection of harmonic oscillators, for instance, in the form of superconducting resonators.
Collapse
Affiliation(s)
- Jukka P. Pekola
- Pico Group, QTF Centre of Excellence, Department of Applied Physics, Aalto University, P.O. Box 15100, FI-00076 Aalto, Finland;
| | - Bayan Karimi
- Pico Group, QTF Centre of Excellence, Department of Applied Physics, Aalto University, P.O. Box 15100, FI-00076 Aalto, Finland;
- QTF Centre of Excellence, Department of Physics, Faculty of Science, University of Helsinki, FI-00014 Helsinki, Finland
| |
Collapse
|
3
|
Grebel J, Yan H, Chou MH, Andersson G, Conner CR, Joshi YJ, Miller JM, Povey RG, Qiao H, Wu X, Cleland AN. Bidirectional Multiphoton Communication between Remote Superconducting Nodes. PHYSICAL REVIEW LETTERS 2024; 132:047001. [PMID: 38335327 DOI: 10.1103/physrevlett.132.047001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 12/11/2023] [Indexed: 02/12/2024]
Abstract
Quantum communication test beds provide a useful resource for experimentally investigating a variety of communication protocols. Here we demonstrate a superconducting circuit test bed with bidirectional multiphoton state transfer capability using time-domain shaped wave packets. The system we use to achieve this comprises two remote nodes, each including a tunable superconducting transmon qubit and a tunable microwave-frequency resonator, linked by a 2 m-long superconducting coplanar waveguide, which serves as a transmission line. We transfer both individual and superposition Fock states between the two remote nodes, and additionally show that this bidirectional state transfer can be done simultaneously, as well as being used to entangle elements in the two nodes.
Collapse
Affiliation(s)
- Joel Grebel
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
| | - Haoxiong Yan
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
| | - Ming-Han Chou
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
- Department of Physics, University of Chicago, Chicago, Illinois 60637, USA
| | - Gustav Andersson
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
| | - Christopher R Conner
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
| | - Yash J Joshi
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
| | - Jacob M Miller
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
- Department of Physics, University of Chicago, Chicago, Illinois 60637, USA
| | - Rhys G Povey
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
- Department of Physics, University of Chicago, Chicago, Illinois 60637, USA
| | - Hong Qiao
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
| | - Xuntao Wu
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
| | - Andrew N Cleland
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
- Center for Molecular Engineering, Argonne National Laboratory, Lemont, Illinois 60439, USA
| |
Collapse
|
4
|
Yan H, Zhong Y, Chang HS, Bienfait A, Chou MH, Conner CR, Dumur É, Grebel J, Povey RG, Cleland AN. Entanglement Purification and Protection in a Superconducting Quantum Network. PHYSICAL REVIEW LETTERS 2022; 128:080504. [PMID: 35275688 DOI: 10.1103/physrevlett.128.080504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Accepted: 01/10/2022] [Indexed: 06/14/2023]
Abstract
High-fidelity quantum entanglement is a key resource for quantum communication and distributed quantum computing, enabling quantum state teleportation, dense coding, and quantum encryption. Any sources of decoherence in the communication channel, however, degrade entanglement fidelity, thereby increasing the error rates of entangled state protocols. Entanglement purification provides a method to alleviate these nonidealities by distilling impure states into higher-fidelity entangled states. Here we demonstrate the entanglement purification of Bell pairs shared between two remote superconducting quantum nodes connected by a moderately lossy, 1-meter long superconducting communication cable. We use a purification process to correct the dominant amplitude damping errors caused by transmission through the cable, with fractional increases in fidelity as large as 25%, achieved for higher damping errors. The best final fidelity the purification achieves is 94.09±0.98%. In addition, we use both dynamical decoupling and Rabi driving to protect the entangled states from local noise, increasing the effective qubit dephasing time by a factor of 4, from 3 to 12 μs. These methods demonstrate the potential for the generation and preservation of very high-fidelity entanglement in a superconducting quantum communication network.
Collapse
Affiliation(s)
- Haoxiong Yan
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
| | - Youpeng Zhong
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
| | - Hung-Shen Chang
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
| | - Audrey Bienfait
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
| | - Ming-Han Chou
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
- Department of Physics, University of Chicago, Chicago, Illinois 60637, USA
| | - Christopher R Conner
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
| | - Étienne Dumur
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
- Center for Molecular Engineering and Material Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Joel Grebel
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
| | - Rhys G Povey
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
- Department of Physics, University of Chicago, Chicago, Illinois 60637, USA
| | - Andrew N Cleland
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
- Center for Molecular Engineering and Material Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| |
Collapse
|
5
|
Fedoseev V, Luna F, Hedgepeth I, Löffler W, Bouwmeester D. Stimulated Raman Adiabatic Passage in Optomechanics. PHYSICAL REVIEW LETTERS 2021; 126:113601. [PMID: 33798387 DOI: 10.1103/physrevlett.126.113601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 02/12/2021] [Indexed: 06/12/2023]
Abstract
In multimode optomechanical systems, the mechanical modes can be coupled via the radiation pressure of the common optical mode, but the fidelity of the state transfer is limited by the optical cavity decay. Here we demonstrate stimulated Raman adiabatic passage (STIRAP) in optomechanics, where the optical mode is not populated during the coherent state transfer between the mechanical modes avoiding this decay channel. We show a state transfer of a coherent mechanical excitation between vibrational modes of a membrane in a high-finesse optical cavity with a transfer efficiency of 86%. Combined with exceptionally high mechanical quality factors, STIRAP between mechanical modes can enable generation, storage, and manipulation of long-lived mechanical quantum states, which is important for quantum information science and for the investigation of macroscopic quantum superpositions.
Collapse
Affiliation(s)
- Vitaly Fedoseev
- Huygens-Kamerlingh Onnes Laboratorium, Leiden University, 2333 CA, Leiden, Netherlands
| | - Fernando Luna
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - Ian Hedgepeth
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| | - Wolfgang Löffler
- Huygens-Kamerlingh Onnes Laboratorium, Leiden University, 2333 CA, Leiden, Netherlands
| | - Dirk Bouwmeester
- Huygens-Kamerlingh Onnes Laboratorium, Leiden University, 2333 CA, Leiden, Netherlands
- Department of Physics, University of California, Santa Barbara, California 93106, USA
| |
Collapse
|
6
|
Zhong Y, Chang HS, Bienfait A, Dumur É, Chou MH, Conner CR, Grebel J, Povey RG, Yan H, Schuster DI, Cleland AN. Deterministic multi-qubit entanglement in a quantum network. Nature 2021; 590:571-575. [PMID: 33627810 DOI: 10.1038/s41586-021-03288-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 12/15/2020] [Indexed: 01/31/2023]
Abstract
The generation of high-fidelity distributed multi-qubit entanglement is a challenging task for large-scale quantum communication and computational networks1-4. The deterministic entanglement of two remote qubits has recently been demonstrated with both photons5-10 and phonons11. However, the deterministic generation and transmission of multi-qubit entanglement has not been demonstrated, primarily owing to limited state-transfer fidelities. Here we report a quantum network comprising two superconducting quantum nodes connected by a one-metre-long superconducting coaxial cable, where each node includes three interconnected qubits. By directly connecting the cable to one qubit in each node, we transfer quantum states between the nodes with a process fidelity of 0.911 ± 0.008. We also prepare a three-qubit Greenberger-Horne-Zeilinger (GHZ) state12-14 in one node and deterministically transfer this state to the other node, with a transferred-state fidelity of 0.656 ± 0.014. We further use this system to deterministically generate a globally distributed two-node, six-qubit GHZ state with a state fidelity of 0.722 ± 0.021. The GHZ state fidelities are clearly above the threshold of 1/2 for genuine multipartite entanglement15, showing that this architecture can be used to coherently link together multiple superconducting quantum processors, providing a modular approach for building large-scale quantum computers16,17.
Collapse
Affiliation(s)
- Youpeng Zhong
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, USA.,Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Hung-Shen Chang
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, USA
| | - Audrey Bienfait
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, USA.,Université de Lyon, ENS de Lyon, Université Claude Bernard, CNRS, Laboratoire de Physique, Lyon, France
| | - Étienne Dumur
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, USA.,Institute for Molecular Engineering and Material Science Division, Argonne National Laboratory, Argonne, IL, USA.,Université Grenoble Alpes, CEA, INAC-Pheliqs, Grenoble, France
| | - Ming-Han Chou
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, USA.,Department of Physics, University of Chicago, Chicago, IL, USA
| | - Christopher R Conner
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, USA
| | - Joel Grebel
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, USA
| | - Rhys G Povey
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, USA.,Department of Physics, University of Chicago, Chicago, IL, USA
| | - Haoxiong Yan
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, USA
| | - David I Schuster
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, USA.,Department of Physics, University of Chicago, Chicago, IL, USA
| | - Andrew N Cleland
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, USA. .,Institute for Molecular Engineering and Material Science Division, Argonne National Laboratory, Argonne, IL, USA.
| |
Collapse
|
7
|
Magnard P, Storz S, Kurpiers P, Schär J, Marxer F, Lütolf J, Walter T, Besse JC, Gabureac M, Reuer K, Akin A, Royer B, Blais A, Wallraff A. Microwave Quantum Link between Superconducting Circuits Housed in Spatially Separated Cryogenic Systems. PHYSICAL REVIEW LETTERS 2020; 125:260502. [PMID: 33449744 DOI: 10.1103/physrevlett.125.260502] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 11/16/2020] [Indexed: 05/26/2023]
Abstract
Superconducting circuits are a strong contender for realizing quantum computing systems and are also successfully used to study quantum optics and hybrid quantum systems. However, their cryogenic operation temperatures and the current lack of coherence-preserving microwave-to-optical conversion solutions have hindered the realization of superconducting quantum networks spanning different cryogenic systems or larger distances. Here, we report the successful operation of a cryogenic waveguide coherently linking transmon qubits located in two dilution refrigerators separated by a physical distance of five meters. We transfer qubit states and generate entanglement on demand with average transfer and target state fidelities of 85.8% and 79.5%, respectively, between the two nodes of this elementary network. Cryogenic microwave links provide an opportunity to scale up systems for quantum computing and create local area superconducting quantum communication networks over length scales of at least tens of meters.
Collapse
Affiliation(s)
- P Magnard
- Department of Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - S Storz
- Department of Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - P Kurpiers
- Department of Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - J Schär
- Department of Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - F Marxer
- Department of Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - J Lütolf
- Department of Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - T Walter
- Department of Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - J-C Besse
- Department of Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - M Gabureac
- Department of Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - K Reuer
- Department of Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - A Akin
- Department of Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - B Royer
- Institut Quantique and Département de Physique, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada
| | - A Blais
- Institut Quantique and Département de Physique, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada
- Canadian Institute for Advanced Research, Toronto, Ontario M5G 1Z8, Canada
| | - A Wallraff
- Department of Physics, ETH Zürich, CH-8093 Zürich, Switzerland
- Quantum Center, ETH Zürich, 8093 Zürich, Switzerland
| |
Collapse
|