1
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Strandberg I, Eriksson AM, Royer B, Kervinen M, Gasparinetti S. Digital Homodyne and Heterodyne Detection for Stationary Bosonic Modes. PHYSICAL REVIEW LETTERS 2024; 133:063601. [PMID: 39178427 DOI: 10.1103/physrevlett.133.063601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 03/20/2024] [Accepted: 07/09/2024] [Indexed: 08/25/2024]
Abstract
Homo- and heterodyne detection are fundamental techniques for measuring propagating electromagnetic fields. However, applying these techniques to stationary fields confined in cavities poses a challenge. As a way to overcome this challenge, we propose to use repeated indirect measurements of a two-level system interacting with the cavity. We demonstrate numerically that the proposed measurement scheme faithfully reproduces measurement statistics of homo- or heterodyne detection. The scheme can be implemented in various physical architectures, including circuit quantum electrodynamics. Our results pave the way for implementation of quantum algorithms requiring linear detection of stationary modes, including quantum verification protocols.
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2
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Valadares F, Huang NN, Chu KTN, Dorogov A, Chua W, Kong L, Song P, Gao YY. On-demand transposition across light-matter interaction regimes in bosonic cQED. Nat Commun 2024; 15:5816. [PMID: 38987273 PMCID: PMC11236968 DOI: 10.1038/s41467-024-50201-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Accepted: 07/02/2024] [Indexed: 07/12/2024] Open
Abstract
The diverse applications of light-matter interactions in science and technology stem from the qualitatively distinct ways these interactions manifest, prompting the development of physical platforms that can interchange between regimes on demand. Bosonic cQED employs the light field of high-Q superconducting cavities coupled to nonlinear circuit elements, harnessing the rich dynamics of their interaction for quantum information processing. However, implementing fast switching of the interaction regime without deteriorating the cavity coherence is a significant challenge. We present an experiment that achieves this feat, combining nanosecond-scale frequency tunability of a transmon coupled to a cavity with lifetime of hundreds of microseconds. Our implementation affords a range of useful capabilities for quantum information processing; from fast creation of cavity Fock states using resonant interaction and interchanging tomography techniques at qualitatively distinct interaction regimes on the fly, to the suppression of unwanted cavity-transmon dynamics during idle evolution. By bringing flux tunability into the bosonic cQED toolkit, our work opens up the possibility to probe the full range of light-matter interaction dynamics within a single platform and provides valuable pathways towards robust and versatile quantum information processing.
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Affiliation(s)
- Fernando Valadares
- Centre for Quantum Technologies, National University of Singapore, Singapore, Singapore.
| | - Ni-Ni Huang
- Centre for Quantum Technologies, National University of Singapore, Singapore, Singapore
| | - Kyle Timothy Ng Chu
- Centre for Quantum Technologies, National University of Singapore, Singapore, Singapore
- Horizon Quantum Computing, Singapore, Singapore
| | - Aleksandr Dorogov
- Centre for Quantum Technologies, National University of Singapore, Singapore, Singapore
| | - Weipin Chua
- Department of Physics, National University of Singapore, Singapore, Singapore
| | - Lingda Kong
- Centre for Quantum Technologies, National University of Singapore, Singapore, Singapore
| | - Pengtao Song
- Centre for Quantum Technologies, National University of Singapore, Singapore, Singapore
| | - Yvonne Y Gao
- Centre for Quantum Technologies, National University of Singapore, Singapore, Singapore.
- Department of Physics, National University of Singapore, Singapore, Singapore.
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3
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Eriksson AM, Sépulcre T, Kervinen M, Hillmann T, Kudra M, Dupouy S, Lu Y, Khanahmadi M, Yang J, Castillo-Moreno C, Delsing P, Gasparinetti S. Universal control of a bosonic mode via drive-activated native cubic interactions. Nat Commun 2024; 15:2512. [PMID: 38509084 PMCID: PMC10954688 DOI: 10.1038/s41467-024-46507-1] [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: 10/18/2023] [Accepted: 02/29/2024] [Indexed: 03/22/2024] Open
Abstract
Linear bosonic modes offer a hardware-efficient alternative for quantum information processing but require access to some nonlinearity for universal control. The lack of nonlinearity in photonics has led to encoded measurement-based quantum computing, which relies on linear operations but requires access to resourceful ('nonlinear') quantum states, such as cubic phase states. In contrast, superconducting microwave circuits offer engineerable nonlinearities but suffer from static Kerr nonlinearity. Here, we demonstrate universal control of a bosonic mode composed of a superconducting nonlinear asymmetric inductive element (SNAIL) resonator, enabled by native nonlinearities in the SNAIL element. We suppress static nonlinearities by operating the SNAIL in the vicinity of its Kerr-free point and dynamically activate nonlinearities up to third order by fast flux pulses. We experimentally realize a universal set of generalized squeezing operations, as well as the cubic phase gate, and exploit them to deterministically prepare a cubic phase state in 60 ns. Our results initiate the experimental field of polynomial quantum computing, in the continuous-variables notion originally introduced by Lloyd and Braunstein.
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Affiliation(s)
- Axel M Eriksson
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, 412 96, Gothenburg, Sweden.
| | - Théo Sépulcre
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, 412 96, Gothenburg, Sweden
| | - Mikael Kervinen
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, 412 96, Gothenburg, Sweden
| | - Timo Hillmann
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, 412 96, Gothenburg, Sweden
| | - Marina Kudra
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, 412 96, Gothenburg, Sweden
| | - Simon Dupouy
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, 412 96, Gothenburg, Sweden
| | - Yong Lu
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, 412 96, Gothenburg, Sweden
- Physikalisches Institut, University of Stuttgart, 70569, Stuttgart, Germany
| | - Maryam Khanahmadi
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, 412 96, Gothenburg, Sweden
| | - Jiaying Yang
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, 412 96, Gothenburg, Sweden
| | - Claudia Castillo-Moreno
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, 412 96, Gothenburg, Sweden
| | - Per Delsing
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, 412 96, Gothenburg, Sweden
| | - Simone Gasparinetti
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, 412 96, Gothenburg, Sweden.
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4
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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.
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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
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5
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He XL, Lu Y, Bao DQ, Xue H, Jiang WB, Wang Z, Roudsari AF, Delsing P, Tsai JS, Lin ZR. Fast generation of Schrödinger cat states using a Kerr-tunable superconducting resonator. Nat Commun 2023; 14:6358. [PMID: 37821443 PMCID: PMC10567735 DOI: 10.1038/s41467-023-42057-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 09/28/2023] [Indexed: 10/13/2023] Open
Abstract
Schrödinger cat states, quantum superpositions of macroscopically distinct classical states, are an important resource for quantum communication, quantum metrology and quantum computation. Especially, cat states in a phase space protected against phase-flip errors can be used as a logical qubit. However, cat states, normally generated in three-dimensional cavities and/or strong multi-photon drives, are facing the challenges of scalability and controllability. Here, we present a strategy to generate and preserve cat states in a coplanar superconducting circuit by the fast modulation of Kerr nonlinearity. At the Kerr-free work point, our cat states are passively preserved due to the vanishing Kerr effect. We are able to prepare a 2-component cat state in our chip-based device with a fidelity reaching 89.1% under a 96 ns gate time. Our scheme shows an excellent route to constructing a chip-based bosonic quantum processor.
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Affiliation(s)
- X L He
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, China
- University of Chinese Academy of Science, 100049, Beijing, China
| | - Yong Lu
- 3rd Physikalisches Institut, University of Stuttgart, 70569, Stuttgart, Germany.
- Microtechnology and Nanoscience, Chalmers University of Technology, SE-412 96, Göteborg, Sweden.
| | - D Q Bao
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, China
- University of Chinese Academy of Science, 100049, Beijing, China
| | - Hang Xue
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, China
- University of Chinese Academy of Science, 100049, Beijing, China
| | - W B Jiang
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, China
- University of Chinese Academy of Science, 100049, Beijing, China
| | - Z Wang
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, China
- University of Chinese Academy of Science, 100049, Beijing, China
| | - A F Roudsari
- Microtechnology and Nanoscience, Chalmers University of Technology, SE-412 96, Göteborg, Sweden
| | - Per Delsing
- Microtechnology and Nanoscience, Chalmers University of Technology, SE-412 96, Göteborg, Sweden
| | - J S Tsai
- Graduate School of Science, Tokyo University of Science, Shinjuku, Tokyo, 162-0825, Japan
- Center for Quantum Computing, RIKEN, Wako, Saitama, 351-0198, Japan
| | - Z R Lin
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, China.
- University of Chinese Academy of Science, 100049, Beijing, China.
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6
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Zheng RH, Ning W, Chen YH, Lü JH, Shen LT, Xu K, Zhang YR, Xu D, Li H, Xia Y, Wu F, Yang ZB, Miranowicz A, Lambert N, Zheng D, Fan H, Nori F, Zheng SB. Observation of a Superradiant Phase Transition with Emergent Cat States. PHYSICAL REVIEW LETTERS 2023; 131:113601. [PMID: 37774281 DOI: 10.1103/physrevlett.131.113601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 05/29/2023] [Accepted: 08/10/2023] [Indexed: 10/01/2023]
Abstract
Superradiant phase transitions (SPTs) are important for understanding light-matter interactions at the quantum level, and play a central role in criticality-enhanced quantum sensing. So far, SPTs have been observed in driven-dissipative systems, but the emergent light fields did not show any nonclassical characteristic due to the presence of strong dissipation. Here we report an experimental demonstration of the SPT featuring the emergence of a highly nonclassical photonic field, realized with a resonator coupled to a superconducting qubit, implementing the quantum Rabi model. We fully characterize the light-matter state by Wigner matrix tomography. The measured matrix elements exhibit quantum interference intrinsic of a photonic mesoscopic superposition, and reveal light-matter entanglement.
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Affiliation(s)
- Ri-Hua Zheng
- Fujian Key Laboratory of Quantum Information and Quantum Optics, College of Physics and Information Engineering, Fuzhou University, Fuzhou, Fujian 350108, China
| | - Wen Ning
- Fujian Key Laboratory of Quantum Information and Quantum Optics, College of Physics and Information Engineering, Fuzhou University, Fuzhou, Fujian 350108, China
| | - Ye-Hong Chen
- Fujian Key Laboratory of Quantum Information and Quantum Optics, College of Physics and Information Engineering, Fuzhou University, Fuzhou, Fujian 350108, China
- Theoretical Quantum Physics Laboratory, RIKEN Cluster for Pioneering Research, Wako-shi, Saitama 351-0198, Japan
- Quantum Information Physics Theory Research Team, RIKEN Center for Quantum Computing (RQC), Wako-shi, Saitama 351-0198, Japan
| | - Jia-Hao Lü
- Fujian Key Laboratory of Quantum Information and Quantum Optics, College of Physics and Information Engineering, Fuzhou University, Fuzhou, Fujian 350108, China
| | - Li-Tuo Shen
- Fujian Key Laboratory of Quantum Information and Quantum Optics, College of Physics and Information Engineering, Fuzhou University, Fuzhou, Fujian 350108, China
| | - Kai Xu
- Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190, China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Yu-Ran Zhang
- Theoretical Quantum Physics Laboratory, RIKEN Cluster for Pioneering Research, Wako-shi, Saitama 351-0198, Japan
- Quantum Information Physics Theory Research Team, RIKEN Center for Quantum Computing (RQC), Wako-shi, Saitama 351-0198, Japan
- School of Physics and Optoelectronics, South China University of Technology, Guangzhou 510640, China
| | - Da Xu
- Interdisciplinary Center of Quantum Information, State Key Laboratory of Modern Optical Instrumentation and Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University, Hangzhou 310027, China
| | - Hekang Li
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Yan Xia
- Fujian Key Laboratory of Quantum Information and Quantum Optics, College of Physics and Information Engineering, Fuzhou University, Fuzhou, Fujian 350108, China
| | - Fan Wu
- Fujian Key Laboratory of Quantum Information and Quantum Optics, College of Physics and Information Engineering, Fuzhou University, Fuzhou, Fujian 350108, China
| | - Zhen-Biao Yang
- Fujian Key Laboratory of Quantum Information and Quantum Optics, College of Physics and Information Engineering, Fuzhou University, Fuzhou, Fujian 350108, China
| | - Adam Miranowicz
- Theoretical Quantum Physics Laboratory, RIKEN Cluster for Pioneering Research, Wako-shi, Saitama 351-0198, Japan
- Institute of Spintronics and Quantum Information, Faculty of Physics, Adam Mickiewicz University, 61-614 Poznań, Poland
| | - Neill Lambert
- Theoretical Quantum Physics Laboratory, RIKEN Cluster for Pioneering Research, Wako-shi, Saitama 351-0198, Japan
| | - Dongning Zheng
- Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190, China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Heng Fan
- Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190, China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Franco Nori
- Theoretical Quantum Physics Laboratory, RIKEN Cluster for Pioneering Research, Wako-shi, Saitama 351-0198, Japan
- Quantum Information Physics Theory Research Team, RIKEN Center for Quantum Computing (RQC), Wako-shi, Saitama 351-0198, Japan
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109-1040, USA
| | - Shi-Biao Zheng
- Fujian Key Laboratory of Quantum Information and Quantum Optics, College of Physics and Information Engineering, Fuzhou University, Fuzhou, Fujian 350108, China
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7
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He X, Zhao WT, Lv WC, Peng CH, Sun Z, Sun YN, Su QP, Yang CP. Experimental demonstration of deterministic quantum search for multiple marked states without adjusting the oracle. OPTICS LETTERS 2023; 48:4428-4431. [PMID: 37656520 DOI: 10.1364/ol.497599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 07/30/2023] [Indexed: 09/03/2023]
Abstract
Grover's search algorithm is a well-known quantum algorithm that has been extensively studied and improved to increase its success rate and enhance its flexibility. However, most improved search algorithms require an adjustment of the oracle, which may not be feasible in practical problem-solving scenarios. In this work, we report an experimental demonstration of a deterministic quantum search for multiple marked states without adjusting the oracle. A linear optical setup is designed to search for two marked states, one in a 16-state database with an initial equal-superposition state and the other in an 8-state database with different initial nonequal-superposition states. The evolution of the probability of finding each state in the database is also measured and displayed. Our experimental results agree well with the theoretical predictions, thereby proving the feasibility of the search protocol and the implementation scheme. This work is a pioneering experimental demonstration of deterministic quantum search for multiple marked states without adjusting the oracle.
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8
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Mandal A, Taylor MA, Weight BM, Koessler ER, Li X, Huo P. Theoretical Advances in Polariton Chemistry and Molecular Cavity Quantum Electrodynamics. Chem Rev 2023; 123:9786-9879. [PMID: 37552606 PMCID: PMC10450711 DOI: 10.1021/acs.chemrev.2c00855] [Citation(s) in RCA: 31] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Indexed: 08/10/2023]
Abstract
When molecules are coupled to an optical cavity, new light-matter hybrid states, so-called polaritons, are formed due to quantum light-matter interactions. With the experimental demonstrations of modifying chemical reactivities by forming polaritons under strong light-matter interactions, theorists have been encouraged to develop new methods to simulate these systems and discover new strategies to tune and control reactions. This review summarizes some of these exciting theoretical advances in polariton chemistry, in methods ranging from the fundamental framework to computational techniques and applications spanning from photochemistry to vibrational strong coupling. Even though the theory of quantum light-matter interactions goes back to the midtwentieth century, the gaps in the knowledge of molecular quantum electrodynamics (QED) have only recently been filled. We review recent advances made in resolving gauge ambiguities, the correct form of different QED Hamiltonians under different gauges, and their connections to various quantum optics models. Then, we review recently developed ab initio QED approaches which can accurately describe polariton states in a realistic molecule-cavity hybrid system. We then discuss applications using these method advancements. We review advancements in polariton photochemistry where the cavity is made resonant to electronic transitions to control molecular nonadiabatic excited state dynamics and enable new photochemical reactivities. When the cavity resonance is tuned to the molecular vibrations instead, ground-state chemical reaction modifications have been demonstrated experimentally, though its mechanistic principle remains unclear. We present some recent theoretical progress in resolving this mystery. Finally, we review the recent advances in understanding the collective coupling regime between light and matter, where many molecules can collectively couple to a single cavity mode or many cavity modes. We also lay out the current challenges in theory to explain the observed experimental results. We hope that this review will serve as a useful document for anyone who wants to become familiar with the context of polariton chemistry and molecular cavity QED and thus significantly benefit the entire community.
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Affiliation(s)
- Arkajit Mandal
- Department
of Chemistry, University of Rochester, 120 Trustee Road, Rochester, New York 14627, United States
- Department
of Chemistry, Columbia University, New York, New York 10027, United States
| | - Michael A.D. Taylor
- The
Institute of Optics, Hajim School of Engineering, University of Rochester, Rochester, New York 14627, United States
| | - Braden M. Weight
- Department
of Physics and Astronomy, University of
Rochester, Rochester, New York 14627, United
States
| | - Eric R. Koessler
- Department
of Chemistry, University of Rochester, 120 Trustee Road, Rochester, New York 14627, United States
| | - Xinyang Li
- Department
of Chemistry, University of Rochester, 120 Trustee Road, Rochester, New York 14627, United States
- Theoretical
Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Pengfei Huo
- Department
of Chemistry, University of Rochester, 120 Trustee Road, Rochester, New York 14627, United States
- The
Institute of Optics, Hajim School of Engineering, University of Rochester, Rochester, New York 14627, United States
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9
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Zeng Y, Zhou ZY, Rinaldi E, Gneiting C, Nori F. Approximate Autonomous Quantum Error Correction with Reinforcement Learning. PHYSICAL REVIEW LETTERS 2023; 131:050601. [PMID: 37595216 DOI: 10.1103/physrevlett.131.050601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 06/22/2023] [Indexed: 08/20/2023]
Abstract
Autonomous quantum error correction (AQEC) protects logical qubits by engineered dissipation and thus circumvents the necessity of frequent, error-prone measurement-feedback loops. Bosonic code spaces, where single-photon loss represents the dominant source of error, are promising candidates for AQEC due to their flexibility and controllability. While existing proposals have demonstrated the in-principle feasibility of AQEC with bosonic code spaces, these schemes are typically based on the exact implementation of the Knill-Laflamme conditions and thus require the realization of Hamiltonian distances d≥2. Implementing such Hamiltonian distances requires multiple nonlinear interactions and control fields, rendering these schemes experimentally challenging. Here, we propose a bosonic code for approximate AQEC by relaxing the Knill-Laflamme conditions. Using reinforcement learning (RL), we identify the optimal bosonic set of code words (denoted here by RL code), which, surprisingly, is composed of the Fock states |2⟩ and |4⟩. As we show, the RL code, despite its approximate nature, successfully suppresses single-photon loss, reducing it to an effective dephasing process that well surpasses the break-even threshold. It may thus provide a valuable building block toward full error protection. The error-correcting Hamiltonian, which includes ancilla systems that emulate the engineered dissipation, is entirely based on the Hamiltonian distance d=1, significantly reducing model complexity. Single-qubit gates are implemented in the RL code with a maximum distance d_{g}=2.
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Affiliation(s)
- Yexiong Zeng
- Theoretical Quantum Physics Laboratory, Cluster for Pioneering Research, RIKEN, Wakoshi, Saitama 351-0198, Japan
- Quantum Computing Center, RIKEN, Wakoshi, Saitama 351-0198, Japan
| | - Zheng-Yang Zhou
- Theoretical Quantum Physics Laboratory, Cluster for Pioneering Research, RIKEN, Wakoshi, Saitama 351-0198, Japan
| | - Enrico Rinaldi
- Theoretical Quantum Physics Laboratory, Cluster for Pioneering Research, RIKEN, Wakoshi, Saitama 351-0198, Japan
- Quantum Computing Center, RIKEN, Wakoshi, Saitama 351-0198, Japan
- Quantinuum K.K., Otemachi Financial City Grand Cube 3F, 1-9-2 Otemachi, Chiyoda-ku, Tokyo, Japan
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109-1040, USA
- Interdisciplinary Theoretical and Mathematical Sciences Program (iTHEMS), RIKEN, Wakoshi, Saitama 351-0198, Japan
| | - Clemens Gneiting
- Theoretical Quantum Physics Laboratory, Cluster for Pioneering Research, RIKEN, Wakoshi, Saitama 351-0198, Japan
- Quantum Computing Center, RIKEN, Wakoshi, Saitama 351-0198, Japan
| | - Franco Nori
- Theoretical Quantum Physics Laboratory, Cluster for Pioneering Research, RIKEN, Wakoshi, Saitama 351-0198, Japan
- Quantum Computing Center, RIKEN, Wakoshi, Saitama 351-0198, Japan
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109-1040, USA
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10
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Xu D, Gu XK, Li HK, Weng YC, Wang YP, Li J, Wang H, Zhu SY, You JQ. Quantum Control of a Single Magnon in a Macroscopic Spin System. PHYSICAL REVIEW LETTERS 2023; 130:193603. [PMID: 37243655 DOI: 10.1103/physrevlett.130.193603] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Accepted: 04/17/2023] [Indexed: 05/29/2023]
Abstract
Nonclassical quantum states are the pivotal features of a quantum system that differs from its classical counterpart. However, the generation and coherent control of quantum states in a macroscopic spin system remain an outstanding challenge. Here we experimentally demonstrate the quantum control of a single magnon in a macroscopic spin system (i.e., 1 mm-diameter yttrium-iron-garnet sphere) coupled to a superconducting qubit via a microwave cavity. By tuning the qubit frequency in situ via the Autler-Townes effect, we manipulate this single magnon to generate its nonclassical quantum states, including the single-magnon state and the superposition of single-magnon state and vacuum (zero magnon) state. Moreover, we confirm the deterministic generation of these nonclassical states by Wigner tomography. Our experiment offers the first reported deterministic generation of the nonclassical quantum states in a macroscopic spin system and paves a way to explore its promising applications in quantum engineering.
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Affiliation(s)
- Da Xu
- Interdisciplinary Center of Quantum Information, State Key Laboratory of Modern Optical Instrumentation and Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University, Hangzhou 310027, China
| | - Xu-Ke Gu
- Interdisciplinary Center of Quantum Information, State Key Laboratory of Modern Optical Instrumentation and Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University, Hangzhou 310027, China
| | - He-Kang Li
- Interdisciplinary Center of Quantum Information, State Key Laboratory of Modern Optical Instrumentation and Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University, Hangzhou 310027, China
| | - Yuan-Chao Weng
- Interdisciplinary Center of Quantum Information, State Key Laboratory of Modern Optical Instrumentation and Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University, Hangzhou 310027, China
| | - Yi-Pu Wang
- Interdisciplinary Center of Quantum Information, State Key Laboratory of Modern Optical Instrumentation and Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University, Hangzhou 310027, China
| | - Jie Li
- Interdisciplinary Center of Quantum Information, State Key Laboratory of Modern Optical Instrumentation and Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University, Hangzhou 310027, China
| | - H Wang
- Interdisciplinary Center of Quantum Information, State Key Laboratory of Modern Optical Instrumentation and Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University, Hangzhou 310027, China
- Hefei National Laboratory, Hefei 230088, China
| | - Shi-Yao Zhu
- Interdisciplinary Center of Quantum Information, State Key Laboratory of Modern Optical Instrumentation and Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University, Hangzhou 310027, China
- Hefei National Laboratory, Hefei 230088, China
| | - J Q You
- Interdisciplinary Center of Quantum Information, State Key Laboratory of Modern Optical Instrumentation and Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University, Hangzhou 310027, China
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11
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Yu C, Ahmed Z, Frisch JC, Henderson SW, Silva-Feaver M, Arnold K, Brown D, Connors J, Cukierman AJ, D'Ewart JM, Dober BJ, Dusatko JE, Haller G, Herbst R, Hilton GC, Hubmayr J, Irwin KD, Kuo CL, Mates JAB, Ruckman L, Ullom J, Vale L, Van Winkle DD, Vasquez J, Young E. SLAC microresonator RF (SMuRF) electronics: A tone-tracking readout system for superconducting microwave resonator arrays. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2023; 94:014712. [PMID: 36725567 DOI: 10.1063/5.0125084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 01/03/2023] [Indexed: 06/18/2023]
Abstract
We describe the newest generation of the SLAC Microresonator RF (SMuRF) electronics, a warm digital control and readout system for microwave-frequency resonator-based cryogenic detector and multiplexer systems, such as microwave superconducting quantum interference device multiplexers (μmux) or microwave kinetic inductance detectors. Ultra-sensitive measurements in particle physics and astronomy increasingly rely on large arrays of cryogenic sensors, which in turn necessitate highly multiplexed readout and accompanying room-temperature electronics. Microwave-frequency resonators are a popular tool for cryogenic multiplexing, with the potential to multiplex thousands of detector channels on one readout line. The SMuRF system provides the capability for reading out up to 3328 channels across a 4-8 GHz bandwidth. Notably, the SMuRF system is unique in its implementation of a closed-loop tone-tracking algorithm that minimizes RF power transmitted to the cold amplifier, substantially relaxing system linearity requirements and effective noise from intermodulation products. Here, we present a description of the hardware, firmware, and software systems of the SMuRF electronics, comparing achieved performance with science-driven design requirements. In particular, we focus on the case of large-channel-count, low-bandwidth applications, but the system has been easily reconfigured for high-bandwidth applications. The system described here has been successfully deployed in lab settings and field sites around the world and is baselined for use on upcoming large-scale observatories.
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Affiliation(s)
- Cyndia Yu
- Department of Physics, Stanford University, Stanford, California 94305, USA
| | - Zeeshan Ahmed
- Kavli Institute for Particle Astrophysics and Cosmology, Stanford, California 94305, USA
| | - Josef C Frisch
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Shawn W Henderson
- Kavli Institute for Particle Astrophysics and Cosmology, Stanford, California 94305, USA
| | - Max Silva-Feaver
- Department of Physics, University of California San Diego, La Jolla, California 92093, USA
| | - Kam Arnold
- Department of Physics, University of California San Diego, La Jolla, California 92093, USA
| | - David Brown
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Jake Connors
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - Ari J Cukierman
- Department of Physics, Stanford University, Stanford, California 94305, USA
| | - J Mitch D'Ewart
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Bradley J Dober
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - John E Dusatko
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Gunther Haller
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Ryan Herbst
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Gene C Hilton
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - Johannes Hubmayr
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - Kent D Irwin
- Department of Physics, Stanford University, Stanford, California 94305, USA
| | - Chao-Lin Kuo
- Department of Physics, Stanford University, Stanford, California 94305, USA
| | - John A B Mates
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - Larry Ruckman
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Joel Ullom
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - Leila Vale
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | | | - Jesus Vasquez
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Edward Young
- Department of Physics, Stanford University, Stanford, California 94305, USA
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12
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Deng J, Dong H, Zhang C, Wu Y, Yuan J, Zhu X, Jin F, Li H, Wang Z, Cai H, Song C, Wang H, You JQ, Wang DW. Observing the quantum topology of light. Science 2022; 378:966-971. [DOI: 10.1126/science.ade6219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Topological photonics provides a powerful platform to explore topological physics beyond traditional electronic materials and shows promising applications in light transport and lasers. Classical degrees of freedom are routinely used to construct topological light modes in real or synthetic dimensions. Beyond the classical topology, the inherent quantum nature of light provides a wealth of fundamentally distinct topological states. Here we implement experiments on topological states of quantized light in a superconducting circuit, with which one- and two-dimensional Fock-state lattices are constructed. We realize rich topological physics including topological zero-energy states of the Su-Schrieffer-Heeger model, strain-induced pseudo-Landau levels, valley Hall effect, and Haldane chiral edge currents. Our study extends the topological states of light to the quantum regime, bridging topological phases of condensed-matter physics with circuit quantum electrodynamics, and offers a freedom in controlling the quantum states of multiple resonators.
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Affiliation(s)
- Jinfeng Deng
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, and Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University, Hangzhou 310027, China
| | - Hang Dong
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, and Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University, Hangzhou 310027, China
| | - Chuanyu Zhang
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, and Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University, Hangzhou 310027, China
| | - Yaozu Wu
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, and Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University, Hangzhou 310027, China
| | - Jiale Yuan
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, and Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University, Hangzhou 310027, China
| | - Xuhao Zhu
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, and Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University, Hangzhou 310027, China
| | - Feitong Jin
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, and Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University, Hangzhou 310027, China
| | - Hekang Li
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, and Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University, Hangzhou 310027, China
| | - Zhen Wang
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, and Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University, Hangzhou 310027, China
- Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 311215, China
- Hefei National Laboratory, Hefei 230088, China
| | - Han Cai
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, and Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University, Hangzhou 310027, China
| | - Chao Song
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, and Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University, Hangzhou 310027, China
| | - H. Wang
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, and Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University, Hangzhou 310027, China
- Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 311215, China
- Hefei National Laboratory, Hefei 230088, China
| | - J. Q. You
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, and Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University, Hangzhou 310027, China
| | - Da-Wei Wang
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, and Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University, Hangzhou 310027, China
- Hefei National Laboratory, Hefei 230088, China
- CAS Center of Excellence in Topological Quantum Computation, Beijing 100190, China
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13
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Xu Q, Blencowe MP. Optomechanical Quantum Entanglement Mediated by Acoustic Phonon Fields. PHYSICAL REVIEW LETTERS 2022; 129:203604. [PMID: 36462021 DOI: 10.1103/physrevlett.129.203604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 05/30/2022] [Accepted: 10/17/2022] [Indexed: 06/17/2023]
Abstract
We present exact solutions for the quantum time evolution of two spatially separated, local inductor-capacitor (LC) oscillators that are coupled optomechanically to a long elastic strip that functions as a quantum thermal acoustic field environment. We show that the optomechanical coupling to the acoustic environment gives rise to causal entanglement dynamics between the two LC oscillators in the absence of resonant photon exchange between them, and that significant entanglement develops regardless of the environment temperature. Such a process establishes that distributed entanglement may be generated between superconducting qubits via a connected phonon bus bar, without the need for resonant phonon release and capture.
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Affiliation(s)
- Qidong Xu
- Department of Physics and Astronomy, Dartmouth College, Hanover, New Hampshire 03755, USA
| | - M P Blencowe
- Department of Physics and Astronomy, Dartmouth College, Hanover, New Hampshire 03755, USA
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14
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Kounalakis M, Bauer GEW, Blanter YM. Analog Quantum Control of Magnonic Cat States on a Chip by a Superconducting Qubit. PHYSICAL REVIEW LETTERS 2022; 129:037205. [PMID: 35905351 DOI: 10.1103/physrevlett.129.037205] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Accepted: 06/22/2022] [Indexed: 06/15/2023]
Abstract
We propose to directly and quantum-coherently couple a superconducting transmon qubit to magnons-the quanta of the collective spin excitations, in a nearby magnetic particle. The magnet's stray field couples to the qubit via a superconducting quantum interference device. We predict a resonant magnon-qubit exchange and a nonlinear radiation-pressure interaction that are both stronger than dissipation rates and tunable by an external flux bias. We additionally demonstrate a quantum control scheme that generates magnon-qubit entanglement and magnonic Schrödinger cat states with high fidelity.
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Affiliation(s)
- Marios Kounalakis
- Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, Netherlands
| | - Gerrit E W Bauer
- Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, Netherlands
- WPI-AIMR, Tohoku University, 2-1-1, Katahira, Sendai 980-8577, Japan
- Kavli Institute for Theoretical Sciences, University of the Chinese Academy of Sciences, 100190 Beijing, China
| | - Yaroslav M Blanter
- Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, Netherlands
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15
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Yu H, Jing L, Hua T, Xu W. Temperature and power characteristics of quarter-wavelength superconducting coplanar waveguide resonator. SN APPLIED SCIENCES 2022. [DOI: 10.1007/s42452-022-04956-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
AbstractA quarter wavelength superconducting aluminum film coplanar waveguide resonator with a high-quality factor was designed and fabricated. Furthermore, its resonant frequency and quality as a function of temperatures and exciting powers were investigated. The experimental results showed that the resonance frequency decreases about 1% with the increase of temperature from 50 mk to 1 K, and the load quality factor of the resonator also decreases. The resonant frequency decreases with power from − 120 to − 70 dBm. The quality factor increases with increased excitation power due to the loss decreases and nonlinearity. The results are consistent with the theoretical analysis of the surface impedance model.
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16
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Makarov D, Volkov OM, Kákay A, Pylypovskyi OV, Budinská B, Dobrovolskiy OV. New Dimension in Magnetism and Superconductivity: 3D and Curvilinear Nanoarchitectures. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2101758. [PMID: 34705309 DOI: 10.1002/adma.202101758] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 05/16/2021] [Indexed: 06/13/2023]
Abstract
Traditionally, the primary field, where curvature has been at the heart of research, is the theory of general relativity. In recent studies, however, the impact of curvilinear geometry enters various disciplines, ranging from solid-state physics over soft-matter physics, chemistry, and biology to mathematics, giving rise to a plethora of emerging domains such as curvilinear nematics, curvilinear studies of cell biology, curvilinear semiconductors, superfluidity, optics, 2D van der Waals materials, plasmonics, magnetism, and superconductivity. Here, the state of the art is summarized and prospects for future research in curvilinear solid-state systems exhibiting such fundamental cooperative phenomena as ferromagnetism, antiferromagnetism, and superconductivity are outlined. Highlighting the recent developments and current challenges in theory, fabrication, and characterization of curvilinear micro- and nanostructures, special attention is paid to perspective research directions entailing new physics and to their strong application potential. Overall, the perspective is aimed at crossing the boundaries between the magnetism and superconductivity communities and drawing attention to the conceptual aspects of how extension of structures into the third dimension and curvilinear geometry can modify existing and aid launching novel functionalities. In addition, the perspective should stimulate the development and dissemination of research and development oriented techniques to facilitate rapid transitions from laboratory demonstrations to industry-ready prototypes and eventual products.
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Affiliation(s)
- Denys Makarov
- Helmholtz-Zentrum Dresden - Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, 01328, Dresden, Germany
| | - Oleksii M Volkov
- Helmholtz-Zentrum Dresden - Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, 01328, Dresden, Germany
| | - Attila Kákay
- Helmholtz-Zentrum Dresden - Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, 01328, Dresden, Germany
| | - Oleksandr V Pylypovskyi
- Helmholtz-Zentrum Dresden - Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, 01328, Dresden, Germany
- Kyiv Academic University, Kyiv, 03142, Ukraine
| | - Barbora Budinská
- Superconductivity and Spintronics Laboratory, Nanomagnetism and Magnonics, Faculty of Physics, University of Vienna, Vienna, 1090, Austria
| | - Oleksandr V Dobrovolskiy
- Superconductivity and Spintronics Laboratory, Nanomagnetism and Magnonics, Faculty of Physics, University of Vienna, Vienna, 1090, Austria
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17
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Enzian G, Freisem L, Price JJ, Svela AØ, Clarke J, Shajilal B, Janousek J, Buchler BC, Lam PK, Vanner MR. Non-Gaussian Mechanical Motion via Single and Multiphonon Subtraction from a Thermal State. PHYSICAL REVIEW LETTERS 2021; 127:243601. [PMID: 34951800 DOI: 10.1103/physrevlett.127.243601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 11/08/2021] [Indexed: 06/14/2023]
Abstract
Quantum optical measurement techniques offer a rich avenue for quantum control of mechanical oscillators via cavity optomechanics. In particular, a powerful yet little explored combination utilizes optical measurements to perform heralded non-Gaussian mechanical state preparation followed by tomography to determine the mechanical phase-space distribution. Here, we experimentally perform heralded single-phonon and multiphonon subtraction via photon counting to a laser-cooled mechanical thermal state with a Brillouin optomechanical system at room temperature and use optical heterodyne detection to measure the s-parametrized Wigner distribution of the non-Gaussian mechanical states generated. The techniques developed here advance the state of the art for optics-based tomography of mechanical states and will be useful for a broad range of applied and fundamental studies that utilize mechanical quantum-state engineering and tomography.
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Affiliation(s)
- G Enzian
- QOLS, Blackett Laboratory, Imperial College London, London SW7 2BW, United Kingdom
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, United Kingdom
- Niels Bohr Institute, University of Copenhagen, Copenhagen 2100, Denmark
| | - L Freisem
- QOLS, Blackett Laboratory, Imperial College London, London SW7 2BW, United Kingdom
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, United Kingdom
| | - J J Price
- QOLS, Blackett Laboratory, Imperial College London, London SW7 2BW, United Kingdom
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, United Kingdom
| | - A Ø Svela
- QOLS, Blackett Laboratory, Imperial College London, London SW7 2BW, United Kingdom
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, United Kingdom
- Max Planck Institute for the Science of Light, Staudtstaße 2, 91058 Erlangen, Germany
| | - J Clarke
- QOLS, Blackett Laboratory, Imperial College London, London SW7 2BW, United Kingdom
| | - B Shajilal
- Centre for Quantum Computation and Communication Technology, Research School of Physics and Engineering, Australian National University, Canberra 2601, Australia
| | - J Janousek
- Centre for Quantum Computation and Communication Technology, Research School of Physics and Engineering, Australian National University, Canberra 2601, Australia
| | - B C Buchler
- Centre for Quantum Computation and Communication Technology, Research School of Physics and Engineering, Australian National University, Canberra 2601, Australia
| | - P K Lam
- Centre for Quantum Computation and Communication Technology, Research School of Physics and Engineering, Australian National University, Canberra 2601, Australia
| | - M R Vanner
- QOLS, Blackett Laboratory, Imperial College London, London SW7 2BW, United Kingdom
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, United Kingdom
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18
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Ma WL, Puri S, Schoelkopf RJ, Devoret MH, Girvin SM, Jiang L. Quantum control of bosonic modes with superconducting circuits. Sci Bull (Beijing) 2021; 66:1789-1805. [PMID: 36654386 DOI: 10.1016/j.scib.2021.05.024] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 05/20/2021] [Accepted: 05/24/2021] [Indexed: 01/20/2023]
Abstract
Bosonic modes have wide applications in various quantum technologies, such as optical photons for quantum communication, magnons in spin ensembles for quantum information storage and mechanical modes for reversible microwave-to-optical quantum transduction. There is emerging interest in utilizing bosonic modes for quantum information processing, with circuit quantum electrodynamics (circuit QED) as one of the leading architectures. Quantum information can be encoded into subspaces of a bosonic superconducting cavity mode with long coherence time. However, standard Gaussian operations (e.g., beam splitting and two-mode squeezing) are insufficient for universal quantum computing. The major challenge is to introduce additional nonlinear control beyond Gaussian operations without adding significant bosonic loss or decoherence. Here we review recent advances in universal control of a single bosonic code with superconducting circuits, including unitary control, quantum feedback control, driven-dissipative control and holonomic dissipative control. Various approaches to entangling different bosonic modes are also discussed.
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Affiliation(s)
- Wen-Long Ma
- State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China; Pritzker School of Molecular Engineering, University of Chicago, Illinois 60637, USA
| | - Shruti Puri
- Department of Applied Physics and Physics, Yale University, New Haven, Connecticut 06511, USA; Yale Quantum Institute, Yale University, New Haven, Connecticut 06511, USA
| | - Robert J Schoelkopf
- Department of Applied Physics and Physics, Yale University, New Haven, Connecticut 06511, USA; Yale Quantum Institute, Yale University, New Haven, Connecticut 06511, USA
| | - Michel H Devoret
- Department of Applied Physics and Physics, Yale University, New Haven, Connecticut 06511, USA; Yale Quantum Institute, Yale University, New Haven, Connecticut 06511, USA
| | - S M Girvin
- Department of Applied Physics and Physics, Yale University, New Haven, Connecticut 06511, USA; Yale Quantum Institute, Yale University, New Haven, Connecticut 06511, USA
| | - Liang Jiang
- Pritzker School of Molecular Engineering, University of Chicago, Illinois 60637, USA.
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19
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Cai W, Han J, Hu L, Ma Y, Mu X, Wang W, Xu Y, Hua Z, Wang H, Song YP, Zhang JN, Zou CL, Sun L. High-Efficiency Arbitrary Quantum Operation on a High-Dimensional Quantum System. PHYSICAL REVIEW LETTERS 2021; 127:090504. [PMID: 34506165 DOI: 10.1103/physrevlett.127.090504] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 08/02/2021] [Indexed: 06/13/2023]
Abstract
The ability to manipulate quantum systems lies at the heart of the development of quantum technology. The ultimate goal of quantum control is to realize arbitrary quantum operations (AQUOs) for all possible open quantum system dynamics. However, the demanding extra physical resources impose great obstacles. Here, we experimentally demonstrate a universal approach of AQUO on a photonic qudit with the minimum physical resource of a two-level ancilla and a log_{2}d-scale circuit depth for a d-dimensional system. The AQUO is then applied in a quantum trajectory simulation for quantum subspace stabilization and quantum Zeno dynamics, as well as incoherent manipulation and generalized measurements of the qudit. Therefore, the demonstrated AQUO for complete quantum control would play an indispensable role in quantum information science.
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Affiliation(s)
- W Cai
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - J Han
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - L Hu
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - Y Ma
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - X Mu
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - W Wang
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - Y Xu
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - Z Hua
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - H Wang
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - Y P Song
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - J-N Zhang
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
| | - C-L Zou
- Key Laboratory of Quantum Information, CAS, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - L Sun
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
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20
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Zhang DB, Zhang GQ, Xue ZY, Zhu SL, Wang ZD. Continuous-Variable Assisted Thermal Quantum Simulation. PHYSICAL REVIEW LETTERS 2021; 127:020502. [PMID: 34296925 DOI: 10.1103/physrevlett.127.020502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 11/30/2020] [Accepted: 06/10/2021] [Indexed: 06/13/2023]
Abstract
Simulation of a quantum many-body system at finite temperatures is crucially important but quite challenging. Here we present an experimentally feasible quantum algorithm assisted with continuous variable for simulating quantum systems at finite temperatures. Our algorithm has a time complexity scaling polynomially with the inverse temperature and the desired accuracy. We demonstrate the quantum algorithm by simulating a finite temperature phase diagram of the quantum Ising and Kitaev models. It is found that the important crossover phase diagram of the Kitaev ring can be accurately simulated by a quantum computer with only a few qubits and thus the algorithm may be implementable on current quantum processors. We further propose a protocol with superconducting or trapped ion quantum computers.
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Affiliation(s)
- Dan-Bo Zhang
- Guangdong-Hong Kong Joint Laboratory of Quantum Matter, Frontier Research Institute for Physics, South China Normal University, Guangzhou 510006, China
- Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006, China
| | - Guo-Qing Zhang
- Guangdong-Hong Kong Joint Laboratory of Quantum Matter, Frontier Research Institute for Physics, South China Normal University, Guangzhou 510006, China
- Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006, China
| | - Zheng-Yuan Xue
- Guangdong-Hong Kong Joint Laboratory of Quantum Matter, Frontier Research Institute for Physics, South China Normal University, Guangzhou 510006, China
- Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006, China
| | - Shi-Liang Zhu
- Guangdong-Hong Kong Joint Laboratory of Quantum Matter, Frontier Research Institute for Physics, South China Normal University, Guangzhou 510006, China
- Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006, China
| | - Z D Wang
- Guangdong-Hong Kong Joint Laboratory of Quantum Matter, Department of Physics, and HKU-UCAS Joint Institute for Theoretical and Computational Physics at Hong Kong, The University of Hong Kong, Pokfulam Road, Hong Kong, China
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21
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Keller J, Hou PY, McCormick KC, Cole DC, Erickson SD, Wu JJ, Wilson AC, Leibfried D. Quantum Harmonic Oscillator Spectrum Analyzers. PHYSICAL REVIEW LETTERS 2021; 126:250507. [PMID: 34241508 PMCID: PMC10807510 DOI: 10.1103/physrevlett.126.250507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 04/08/2021] [Indexed: 06/13/2023]
Abstract
Characterization and suppression of noise are essential for the control of harmonic oscillators in the quantum regime. We measure the noise spectrum of a quantum harmonic oscillator from low frequency to near the oscillator resonance by sensing its response to amplitude modulated periodic drives with a qubit. Using the motion of a trapped ion, we experimentally demonstrate two different implementations with combined sensitivity to noise from 500 Hz to 600 kHz. We apply our method to measure the intrinsic noise spectrum of an ion trap potential in a previously unaccessed frequency range.
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Affiliation(s)
- Jonas Keller
- National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA
- Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - Pan-Yu Hou
- National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA
- Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - Katherine C McCormick
- National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA
- Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - Daniel C Cole
- National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA
| | - Stephen D Erickson
- National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA
- Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - Jenny J Wu
- National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA
- Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - Andrew C Wilson
- National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA
| | - Dietrich Leibfried
- National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA
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22
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Huang WCW, Batelaan H, Arndt M. Kapitza-Dirac Blockade: A Universal Tool for the Deterministic Preparation of Non-Gaussian Oscillator States. PHYSICAL REVIEW LETTERS 2021; 126:253601. [PMID: 34241507 DOI: 10.1103/physrevlett.126.253601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 12/20/2020] [Accepted: 05/24/2021] [Indexed: 06/13/2023]
Abstract
Harmonic oscillators count among the most fundamental quantum systems with important applications in molecular physics, nanoparticle trapping, and quantum information processing. Their equidistant energy level spacing is often a desired feature, but at the same time a challenge if the goal is to deterministically populate specific eigenstates. Here, we show how interference in the transition amplitudes in a bichromatic laser field can suppress the sequential climbing of harmonic oscillator states (Kapitza-Dirac blockade) and achieve selective excitation of energy eigenstates, cat states, and other non-Gaussian states. This technique can transform the harmonic oscillator into a coherent two-level system or be used to build a large-momentum-transfer beam splitter for matter waves. To illustrate the universality of the concept, we discuss feasible experiments that cover many orders of magnitude in mass, from single electrons over large molecules to dielectric nanoparticles.
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Affiliation(s)
- Wayne Cheng-Wei Huang
- Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, USA
| | - Herman Batelaan
- Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - Markus Arndt
- Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria
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23
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Cai ML, Liu ZD, Zhao WD, Wu YK, Mei QX, Jiang Y, He L, Zhang X, Zhou ZC, Duan LM. Observation of a quantum phase transition in the quantum Rabi model with a single trapped ion. Nat Commun 2021; 12:1126. [PMID: 33602942 PMCID: PMC7893029 DOI: 10.1038/s41467-021-21425-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 01/22/2021] [Indexed: 11/30/2022] Open
Abstract
Quantum phase transitions (QPTs) are usually associated with many-body systems in the thermodynamic limit when their ground states show abrupt changes at zero temperature with variation of a parameter in the Hamiltonian. Recently it has been realized that a QPT can also occur in a system composed of only a two-level atom and a single-mode bosonic field, described by the quantum Rabi model (QRM). Here we report an experimental demonstration of a QPT in the QRM using a 171Yb+ ion in a Paul trap. We measure the spin-up state population and the average phonon number of the ion as two order parameters and observe clear evidence of the phase transition via adiabatic tuning of the coupling between the ion and its spatial motion. An experimental probe of the phase transition in a fundamental quantum optics model without imposing the thermodynamic limit opens up a window for controlled study of QPTs and quantum critical phenomena. Quantum phase transition occurs in many-body systems with abrupt changes in the ground state around zero temperature. Here the authors report signatures of quantum phase transition in single trapped ion that can be described using quantum Rabi model.
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Affiliation(s)
- M-L Cai
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, PR China
| | - Z-D Liu
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, PR China
| | - W-D Zhao
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, PR China
| | - Y-K Wu
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, PR China
| | - Q-X Mei
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, PR China
| | - Y Jiang
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, PR China
| | - L He
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, PR China
| | - X Zhang
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, PR China.,Department of Physics, Renmin University, Beijing, PR China
| | - Z-C Zhou
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, PR China.,Beijing Academy of Quantum Information Sciences, Beijing, PR China
| | - L-M Duan
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, PR China.
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24
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Enzian G, Price JJ, Freisem L, Nunn J, Janousek J, Buchler BC, Lam PK, Vanner MR. Single-Phonon Addition and Subtraction to a Mechanical Thermal State. PHYSICAL REVIEW LETTERS 2021; 126:033601. [PMID: 33543972 DOI: 10.1103/physrevlett.126.033601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 12/07/2020] [Indexed: 06/12/2023]
Abstract
Adding or subtracting a single quantum of excitation to a thermal state of a bosonic system has the counter-intuitive effect of approximately doubling its mean occupation. We perform the first experimental demonstration of this effect outside optics by implementing single-phonon addition and subtraction to a thermal state of a mechanical oscillator via Brillouin optomechanics in an optical whispering-gallery microresonator. Using a detection scheme that combines single-photon counting and optical heterodyne detection, we observe this doubling of the mechanical thermal fluctuations to a high precision. The capabilities of this joint click-dyne detection scheme adds a significant new dimension for optomechanical quantum science and applications.
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Affiliation(s)
- G Enzian
- QOLS, Blackett Laboratory, Imperial College London, London SW7 2BW, United Kingdom
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, United Kingdom
- Niels Bohr Institute, University of Copenhagen, Copenhagen 2100, Denmark
| | - J J Price
- QOLS, Blackett Laboratory, Imperial College London, London SW7 2BW, United Kingdom
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, United Kingdom
- Centre for Photonics and Photonic Materials, Department of Physics, University of Bath, Bath BA2 7AY, United Kingdom
| | - L Freisem
- QOLS, Blackett Laboratory, Imperial College London, London SW7 2BW, United Kingdom
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, United Kingdom
| | - J Nunn
- Centre for Photonics and Photonic Materials, Department of Physics, University of Bath, Bath BA2 7AY, United Kingdom
| | - J Janousek
- Centre for Quantum Computation and Communication Technology, Research School of Physics and Engineering, Australian National University, Canberra 2601, Australia
| | - B C Buchler
- Centre for Quantum Computation and Communication Technology, Research School of Physics and Engineering, Australian National University, Canberra 2601, Australia
| | - P K Lam
- Centre for Quantum Computation and Communication Technology, Research School of Physics and Engineering, Australian National University, Canberra 2601, Australia
| | - M R Vanner
- QOLS, Blackett Laboratory, Imperial College London, London SW7 2BW, United Kingdom
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, United Kingdom
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25
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Khalil EM, Berrada K, Abdel-Khalek S, Al-Barakaty A, Peřina J. Entanglement and entropy squeezing in the system of two qubits interacting with a two-mode field in the context of power low potentials. Sci Rep 2020; 10:19600. [PMID: 33177591 PMCID: PMC7659019 DOI: 10.1038/s41598-020-76059-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 09/24/2020] [Indexed: 11/09/2022] Open
Abstract
We study the dynamics of two non-stationary qubits, allowing for dipole-dipole and Ising-like interplays between them, coupled to quantized fields in the framework of two-mode pair coherent states of power-low potentials. We focus on three particular cases of the coherent states through the exponent parameter taken infinite square, triangular and harmonic potential wells. We examine the possible effects of such features on the evolution of some quantities of current interest, such as population inversion, entanglement among subsystems and squeezing entropy. We show how these quantities can be affected by the qubit-qubit interaction and exponent parameter during the time evolution for both cases of stationary and non-stationary qubits. The obtained results suggest insights about the capability of quantum systems composed of nonstationary qubits to maintain resources in comparison with stationary qubits.
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Affiliation(s)
- E M Khalil
- Department of Mathematics and Statistics, College of Science, Taif University, P.O. Box 11099, Taif, 21944, Saudi Arabia.,Mathematics Department, Faculty of Science, Azhar University, Cairo, Egypt
| | - K Berrada
- Department of Physics, College of Science, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh, Saudi Arabia. .,The Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, Miramare, Trieste, Italy.
| | - S Abdel-Khalek
- Department of Mathematics and Statistics, College of Science, Taif University, P.O. Box 11099, Taif, 21944, Saudi Arabia.,Mathematics Department, Faculty of Science, Sohag University, Sohag, 82524, Egypt
| | - A Al-Barakaty
- Physics Department, The University College at Aljamoum, Umm Al-Qura University, Makkah, Saudi Arabia
| | - J Peřina
- Joint Laboratory of Optics, Department of Optics, Palacký University, 17. Listopadu 50, 77207, Olomouc, Czech Republic
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26
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Hillmann T, Quijandría F, Johansson G, Ferraro A, Gasparinetti S, Ferrini G. Universal Gate Set for Continuous-Variable Quantum Computation with Microwave Circuits. PHYSICAL REVIEW LETTERS 2020; 125:160501. [PMID: 33124848 DOI: 10.1103/physrevlett.125.160501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 09/16/2020] [Indexed: 06/11/2023]
Abstract
We provide an explicit construction of a universal gate set for continuous-variable quantum computation with microwave circuits. Such a universal set has been first proposed in quantum-optical setups, but its experimental implementation has remained elusive in that domain due to the difficulties in engineering strong nonlinearities. Here, we show that a realistic three-wave mixing microwave architecture based on the superconducting nonlinear asymmetric inductive element [Frattini et al., Appl. Phys. Lett. 110, 222603 (2017)APPLAB0003-695110.1063/1.4984142] allows us to overcome this difficulty. As an application, we show that this architecture allows for the generation of a cubic phase state with an experimentally feasible procedure. This work highlights a practical advantage of microwave circuits with respect to optical systems for the purpose of engineering non-Gaussian states and opens the quest for continuous-variable algorithms based on few repetitions of elementary gates from the continuous-variable universal set.
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Affiliation(s)
- Timo Hillmann
- Department of Microtechnology and Nanoscience (MC2), Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
- Institut für Theorie der Statistischen Physik, RWTH Aachen, 52056 Aachen, Germany
| | - Fernando Quijandría
- Department of Microtechnology and Nanoscience (MC2), Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
| | - Göran Johansson
- Department of Microtechnology and Nanoscience (MC2), Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
| | - Alessandro Ferraro
- Centre for Theoretical Atomic, Molecular and Optical Physics, Queen's University Belfast, Belfast BT7 1NN, United Kingdom
| | - Simone Gasparinetti
- Department of Microtechnology and Nanoscience (MC2), Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
| | - Giulia Ferrini
- Department of Microtechnology and Nanoscience (MC2), Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
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27
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McRae CRH, Wang H, Gao J, Vissers MR, Brecht T, Dunsworth A, Pappas DP, Mutus J. Materials loss measurements using superconducting microwave resonators. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:091101. [PMID: 33003823 DOI: 10.1063/5.0017378] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Accepted: 08/20/2020] [Indexed: 06/11/2023]
Abstract
The performance of superconducting circuits for quantum computing is limited by materials losses. In particular, coherence times are typically bounded by two-level system (TLS) losses at single photon powers and millikelvin temperatures. The identification of low loss fabrication techniques, materials, and thin film dielectrics is critical to achieving scalable architectures for superconducting quantum computing. Superconducting microwave resonators provide a convenient qubit proxy for assessing performance and studying TLS loss and other mechanisms relevant to superconducting circuits such as non-equilibrium quasiparticles and magnetic flux vortices. In this review article, we provide an overview of considerations for designing accurate resonator experiments to characterize loss, including applicable types of losses, cryogenic setup, device design, and methods for extracting material and interface losses, summarizing techniques that have been evolving for over two decades. Results from measurements of a wide variety of materials and processes are also summarized. Finally, we present recommendations for the reporting of loss data from superconducting microwave resonators to facilitate materials comparisons across the field.
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Affiliation(s)
- C R H McRae
- Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - H Wang
- Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - J Gao
- Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - M R Vissers
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - T Brecht
- HRL Laboratories, Malibu, California 90265, USA
| | - A Dunsworth
- Google, Inc., Mountain View, California 94043, USA
| | - D P Pappas
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - J Mutus
- Boulder Cryogenic Quantum Testbed, University of Colorado, Boulder, Colorado 80309, USA
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28
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Uria M, Solano P, Hermann-Avigliano C. Deterministic Generation of Large Fock States. PHYSICAL REVIEW LETTERS 2020; 125:093603. [PMID: 32915610 DOI: 10.1103/physrevlett.125.093603] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 08/04/2020] [Indexed: 06/11/2023]
Abstract
We present a protocol to deterministically prepare the electromagnetic field in a large photon number state. The field starts in a coherent state and, through resonant interaction with one or few two-level systems, it evolves into a coherently displaced Fock state without any postselection. We show the feasibility of the scheme under realistic parameters. The presented method opens a door to reach Fock states, with n∼100 and optimal fidelities above 70%, blurring the line between macroscopic and quantum states of the field.
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Affiliation(s)
- M Uria
- Departamento de Física and Millennium Institute for Research in Optics (MIRO), Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago 8370448, Chile
| | - P Solano
- Department of Physics, MIT-Harvard Center for Ultracold Atoms, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
- Departamento de Física, Facultad de Ciencias Fsicas y Matemticas, Universidad de Concepción, Concepción 160-C, Chile
| | - C Hermann-Avigliano
- Departamento de Física and Millennium Institute for Research in Optics (MIRO), Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago 8370448, Chile
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29
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Burlak G, Medina-Ángel G. Applications of a neural network to detect the percolating transitions in a system with variable radius of defects. CHAOS (WOODBURY, N.Y.) 2020; 30:083145. [PMID: 32872808 DOI: 10.1063/5.0010904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 08/12/2020] [Indexed: 06/11/2023]
Abstract
We systematically study the percolation phase transition at the change of concentration of the chaotic defects (pores) in an extended system where the disordered defects additionally have a variable random radius, using the methods of a neural network (NN). Two important parameters appear in such a material: the average value and the variance of the random pore radius, which leads to significant change in the properties of the phase transition compared with conventional percolation. To train a network, we use the spatial structure of a disordered environment (feature class), and the output (label class) indicates the state of the percolation transition. We found high accuracy of the transition prediction (except the narrow threshold area) by the trained network already in the two-dimensional case. We have also employed such a technique for the extended three-dimensional (3D) percolation system. Our simulations showed the high accuracy of prediction in the percolation transition in 3D case too. The considered approach opens up interesting perspectives for using NN to identify the phase transitions in real percolating nanomaterials with a complex cluster structure.
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Affiliation(s)
- Gennadiy Burlak
- CIICAp, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Cuernavaca, Morelos 62210, México
| | - Gustavo Medina-Ángel
- CIICAp, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Cuernavaca, Morelos 62210, México
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30
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Huan TT, Zhou RG, Ian H. Synchronization of two cavity-coupled qubits measured by entanglement. Sci Rep 2020; 10:12975. [PMID: 32737365 PMCID: PMC7395784 DOI: 10.1038/s41598-020-69903-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 07/20/2020] [Indexed: 11/09/2022] Open
Abstract
Some nonlinear radiations such as superfluorescence can be understood as cooperative effects between atoms. We regard cooperative radiations as a manifested effect secondary to the intrinsic synchronization among the two-level atoms and propose the entanglement measure, concurrence, as a time-resolved measure of synchronization. Modeled on two cavity-coupled qubits, the evolved concurrence monotonically increases to a saturated level. The finite duration required for the rising to saturation coincides with the time delay characteristic to the initiation of superfluorescence, showing the role of synchronization in establishing the cooperation among the qubits. We verify concurrence to be a good measure of synchronization by comparing it with asynchronicity computed from the difference between the density matrices of the qubits. We find that the feature of time delay agrees in both measures and is determined by the coupling regimes of the cavity-qubit interaction. Specifically, synchronization is impossible in the weak coupling regime.
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Affiliation(s)
- Tian-Tian Huan
- Institute of Applied Physics and Materials Engineering, University of Macau, Macau, China
| | - Ri-Gui Zhou
- College of Information Engineering, Shanghai Maritime University, Shanghai, 201306, China
| | - Hou Ian
- Institute of Applied Physics and Materials Engineering, University of Macau, Macau, China. .,Zhuhai UM Science & Technology Research Institute, Zhuhai, Guangdong, China.
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31
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Flühmann C, Home JP. Direct Characteristic-Function Tomography of Quantum States of the Trapped-Ion Motional Oscillator. PHYSICAL REVIEW LETTERS 2020; 125:043602. [PMID: 32794777 DOI: 10.1103/physrevlett.125.043602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 06/26/2020] [Indexed: 06/11/2023]
Abstract
We implement direct readout of the symmetric characteristic function of quantum states of the motional oscillation of a trapped calcium ion. Suitably chosen internal state rotations combined with internal state-dependent displacements, based on bichromatic laser fields, map the expectation value of the real or imaginary part of the displacement operator to the internal states, which are subsequently read out. Combining these results provides full information about the symmetric characteristic function. We characterize the technique by applying it to a range of archetypal quantum oscillator states, including displaced and squeezed Gaussian states as well as two and three component superpositions of displaced squeezed states. For each, we discuss relevant features of the characteristic function and Wigner phase-space quasiprobability distribution. The direct reconstruction of these highly nonclassical oscillator states using a reduced number of measurements is an essential tool for understanding and optimizing the control of oscillator systems for quantum sensing and quantum information applications.
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Affiliation(s)
- C Flühmann
- Institute for Quantum Electronics, ETH Zürich, Otto-Stern-Weg 1, 8093 Zürich, Switzerland
| | - J P Home
- Institute for Quantum Electronics, ETH Zürich, Otto-Stern-Weg 1, 8093 Zürich, Switzerland
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32
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Xu Y, Ma Y, Cai W, Mu X, Dai W, Wang W, Hu L, Li X, Han J, Wang H, Song YP, Yang ZB, Zheng SB, Sun L. Demonstration of Controlled-Phase Gates between Two Error-Correctable Photonic Qubits. PHYSICAL REVIEW LETTERS 2020; 124:120501. [PMID: 32281851 DOI: 10.1103/physrevlett.124.120501] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 10/09/2019] [Accepted: 02/28/2020] [Indexed: 06/11/2023]
Abstract
To realize fault-tolerant quantum computing, it is necessary to store quantum information in logical qubits with error correction functions, realized by distributing a logical state among multiple physical qubits or by encoding it in the Hilbert space of a high-dimensional system. Quantum gate operations between these error-correctable logical qubits, which are essential for implementation of any practical quantum computational task, have not been experimentally demonstrated yet. Here we demonstrate a geometric method for realizing controlled-phase gates between two logical qubits encoded in photonic fields stored in cavities. The gates are realized by dispersively coupling an ancillary superconducting qubit to these cavities and driving it to make a cyclic evolution depending on the joint photonic state of the cavities, which produces a conditional geometric phase. We first realize phase gates for photonic qubits with the logical basis states encoded in two quasiorthogonal coherent states, which have important implications for continuous-variable-based quantum computation. Then we use this geometric method to implement a controlled-phase gate between two binomially encoded logical qubits, which have an error-correctable function.
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Affiliation(s)
- Y Xu
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - Y Ma
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - W Cai
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - X Mu
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - W Dai
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - W Wang
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - L Hu
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - X Li
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - J Han
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - H Wang
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - Y P Song
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - Zhen-Biao Yang
- Fujian Key Laboratory of Quantum Information and Quantum Optics, College of Physics and Information Engineering, Fuzhou University, Fuzhou, Fujian 350108, China
| | - Shi-Biao Zheng
- Fujian Key Laboratory of Quantum Information and Quantum Optics, College of Physics and Information Engineering, Fuzhou University, Fuzhou, Fujian 350108, China
| | - L Sun
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
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33
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Hahn T, Wigger D, Kuhn T. Entropy Dynamics of Phonon Quantum States Generated by Optical Excitation of a Two-Level System. ENTROPY 2020; 22:e22030286. [PMID: 33286060 PMCID: PMC7516742 DOI: 10.3390/e22030286] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 02/26/2020] [Accepted: 02/27/2020] [Indexed: 12/04/2022]
Abstract
In quantum physics, two prototypical model systems stand out due to their wide range of applications. These are the two-level system (TLS) and the harmonic oscillator. The former is often an ideal model for confined charge or spin systems and the latter for lattice vibrations, i.e., phonons. Here, we couple these two systems, which leads to numerous fascinating physical phenomena. Practically, we consider different optical excitations and decay scenarios of a TLS, focusing on the generated dynamics of a single phonon mode that couples to the TLS. Special emphasis is placed on the entropy of the different parts of the system, predominantly the phonons. While, without any decay, the entire system is always in a pure state, resulting in a vanishing entropy, the complex interplay between the single parts results in non-vanishing respective entanglement entropies and non-trivial dynamics of them. Taking a decay of the TLS into account leads to a non-vanishing entropy of the full system and additional aspects in its dynamics. We demonstrate that all aspects of the entropy’s behavior can be traced back to the purity of the states and are illustrated by phonon Wigner functions in phase space.
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34
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Forsch M, Stockill R, Wallucks A, Marinković I, Gärtner C, Norte RA, van Otten F, Fiore A, Srinivasan K, Gröblacher S. Microwave-to-optics conversion using a mechanical oscillator in its quantum groundstate. NATURE PHYSICS 2020; 16:10.1038/s41567-019-0673-7. [PMID: 34795789 PMCID: PMC8596963 DOI: 10.1038/s41567-019-0673-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 08/28/2019] [Indexed: 05/03/2023]
Abstract
Conversion between signals in the microwave and optical domains is of great interest both for classical telecommunication, as well as for connecting future superconducting quantum computers into a global quantum network. For quantum applications, the conversion has to be both efficient, as well as operate in a regime of minimal added classical noise. While efficient conversion has been demonstrated using mechanical transducers, they have so far all operated with a substantial thermal noise background. Here, we overcome this limitation and demonstrate coherent conversion between GHz microwave signals and the optical telecom band with a thermal background of less than one phonon. We use an integrated, on-chip electro-opto-mechanical device that couples surface acoustic waves driven by a resonant microwave signal to an optomechanical crystal featuring a 2.7 GHz mechanical mode. We initialize the mechanical mode in its quantum groundstate, which allows us to perform the transduction process with minimal added thermal noise, while maintaining an optomechanical cooperativity >1, so that microwave photons mapped into the mechanical resonator are effectively upconverted to the optical domain. We further verify the preservation of the coherence of the microwave signal throughout the transduction process.
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Affiliation(s)
- Moritz Forsch
- Kavli Institute of Nanoscience, Department of Quantum Nanoscience, Delft University of Technology, 2628CJ Delft, The Netherlands
| | - Robert Stockill
- Kavli Institute of Nanoscience, Department of Quantum Nanoscience, Delft University of Technology, 2628CJ Delft, The Netherlands
| | - Andreas Wallucks
- Kavli Institute of Nanoscience, Department of Quantum Nanoscience, Delft University of Technology, 2628CJ Delft, The Netherlands
| | - Igor Marinković
- Kavli Institute of Nanoscience, Department of Quantum Nanoscience, Delft University of Technology, 2628CJ Delft, The Netherlands
| | - Claus Gärtner
- Kavli Institute of Nanoscience, Department of Quantum Nanoscience, Delft University of Technology, 2628CJ Delft, The Netherlands
- Vienna Center for Quantum Science and Technology (VCQ), Faculty of Physics, University of Vienna, A-1090 Vienna, Austria
| | - Richard A. Norte
- Kavli Institute of Nanoscience, Department of Quantum Nanoscience, Delft University of Technology, 2628CJ Delft, The Netherlands
- Department of Precision and Microsystems Engineering, Delft University of Technology, Mekelweg 2, 2628CD Delft, The Netherlands
| | - Frank van Otten
- Department of Applied Physics and Institute for Photonic Integration, Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven, The Netherlands
| | - Andrea Fiore
- Department of Applied Physics and Institute for Photonic Integration, Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven, The Netherlands
| | - Kartik Srinivasan
- Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - Simon Gröblacher
- Kavli Institute of Nanoscience, Department of Quantum Nanoscience, Delft University of Technology, 2628CJ Delft, The Netherlands
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35
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Dutta S, Cooper NR. Critical Response of a Quantum van der Pol Oscillator. PHYSICAL REVIEW LETTERS 2019; 123:250401. [PMID: 31922802 DOI: 10.1103/physrevlett.123.250401] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Indexed: 06/10/2023]
Abstract
Classical dynamical systems close to a critical point are known to act as efficient sensors due to a strongly nonlinear response. We explore such systems in the quantum regime by modeling a quantum version of a driven van der Pol oscillator. We find the classical response survives down to one excitation quantum. At very weak drives, genuine quantum features arise, including diverging and negative susceptibilities. Further, the linear response is greatly enhanced by using a strong incoherent pump. These results are largely generic and can be probed in current experimental platforms suited for quantum sensing.
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Affiliation(s)
- Shovan Dutta
- T.C.M. Group, Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Nigel R Cooper
- T.C.M. Group, Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, United Kingdom
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Müller C, Cole JH, Lisenfeld J. Towards understanding two-level-systems in amorphous solids: insights from quantum circuits. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2019; 82:124501. [PMID: 31404914 DOI: 10.1088/1361-6633/ab3a7e] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Amorphous solids show surprisingly universal behaviour at low temperatures. The prevailing wisdom is that this can be explained by the existence of two-state defects within the material. The so-called standard tunneling model has become the established framework to explain these results, yet it still leaves the central question essentially unanswered-what are these two-level defects (TLS)? This question has recently taken on a new urgency with the rise of superconducting circuits in quantum computing, circuit quantum electrodynamics, magnetometry, electrometry and metrology. Superconducting circuits made from aluminium or niobium are fundamentally limited by losses due to TLS within the amorphous oxide layers encasing them. On the other hand, these circuits also provide a novel and effective method for studying the very defects which limit their operation. We can now go beyond ensemble measurements and probe individual defects-observing the quantum nature of their dynamics and studying their formation, their behaviour as a function of applied field, strain, temperature and other properties. This article reviews the plethora of recent experimental results in this area and discusses the various theoretical models which have been used to describe the observations. In doing so, it summarises the current approaches to solving this fundamentally important problem in solid-state physics.
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Affiliation(s)
- Clemens Müller
- IBM Research Zurich, 8803 Rüschlikon, Switzerland. Institute for Theoretical Physics, ETH Zürich, 8093 Zürich, Switzerland. ARC Centre of Excellence for Engineered Quantum Systems, School of Mathematics and Physics, The University of Queensland, Brisbane, Queensland 4072, Australia
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38
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Jerger M, Kulikov A, Vasselin Z, Fedorov A. In Situ Characterization of Qubit Control Lines: A Qubit as a Vector Network Analyzer. PHYSICAL REVIEW LETTERS 2019; 123:150501. [PMID: 31702287 DOI: 10.1103/physrevlett.123.150501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Indexed: 06/10/2023]
Abstract
We propose and experimentally realize a technique to measure the transfer function of a control line in the frequency domain using a qubit as a vector network analyzer. Our method requires coupling the line under test to the longitudinal component of the Hamiltonian of the qubit and the ability to induce Rabi oscillations through simultaneous driving of the transverse component. The method can be used to increase the fidelity of entangling gates in a quantum processor. We have demonstrated that by characterizing the "flux" control line of a superconducting transmon qubit in the range from 1 to 450 MHz and using this characterization to improve the fidelity of an entangling cphase gate between two transmon qubits.
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Affiliation(s)
- Markus Jerger
- ARC Centre of Excellence for Engineered Quantum Systems, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Anatoly Kulikov
- ARC Centre of Excellence for Engineered Quantum Systems, The University of Queensland, St Lucia, Queensland 4072, Australia
- School of Mathematics and Physics, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Zénon Vasselin
- ARC Centre of Excellence for Engineered Quantum Systems, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Arkady Fedorov
- ARC Centre of Excellence for Engineered Quantum Systems, The University of Queensland, St Lucia, Queensland 4072, Australia
- School of Mathematics and Physics, University of Queensland, Brisbane, Queensland 4072, Australia
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39
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Heisenberg-limited single-mode quantum metrology in a superconducting circuit. Nat Commun 2019; 10:4382. [PMID: 31558721 PMCID: PMC6763470 DOI: 10.1038/s41467-019-12290-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 08/27/2019] [Indexed: 11/08/2022] Open
Abstract
Two-mode interferometers lay the foundations for quantum metrology. Instead of exploring quantum entanglement in the two-mode interferometers, a single bosonic mode also promises a measurement precision beyond the shot-noise limit (SNL) by taking advantage of the infinite-dimensional Hilbert space of Fock states. Here, we demonstrate a single-mode phase estimation that approaches the Heisenberg limit (HL) unconditionally. Due to the strong dispersive nonlinearity and long coherence time of a microwave cavity, quantum states of the form [Formula: see text] can be generated, manipulated and detected with high fidelities, leading to an experimental phase estimation precision scaling as ∼N-0.94. A 9.1 dB enhancement of the precision over the SNL at N = 12 is achieved, which is only 1.7 dB away from the HL. Our experimental architecture is hardware efficient and can be combined with quantum error correction techniques to fight against decoherence, and thus promises quantum-enhanced sensing in practical applications.
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40
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Stobińska M, Buraczewski A, Moore M, Clements WR, Renema JJ, Nam SW, Gerrits T, Lita A, Kolthammer WS, Eckstein A, Walmsley IA. Quantum interference enables constant-time quantum information processing. SCIENCE ADVANCES 2019; 5:eaau9674. [PMID: 31334346 PMCID: PMC6641944 DOI: 10.1126/sciadv.aau9674] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 06/14/2019] [Indexed: 05/27/2023]
Abstract
It is an open question how fast information processing can be performed and whether quantum effects can speed up the best existing solutions. Signal extraction, analysis, and compression in diagnostics, astronomy, chemistry, and broadcasting build on the discrete Fourier transform. It is implemented with the fast Fourier transform (FFT) algorithm that assumes a periodic input of specific lengths, which rarely holds true. A lesser-known transform, the Kravchuk-Fourier (KT), allows one to operate on finite strings of arbitrary length. It is of high demand in digital image processing and computer vision but features a prohibitive runtime. Here, we report a one-step computation of a fractional quantum KT. The quantum d-nary (qudit) architecture we use comprises only one gate and offers processing time independent of the input size. The gate may use a multiphoton Hong-Ou-Mandel effect. Existing quantum technologies may scale it up toward diverse applications.
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Affiliation(s)
- M. Stobińska
- Institute of Theoretical Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland
| | - A. Buraczewski
- Institute of Theoretical Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland
| | - M. Moore
- Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, UK
| | - W. R. Clements
- Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, UK
| | - J. J. Renema
- Complex Photonic Systems (COPS), MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, Netherlands
| | - S. W. Nam
- National Institute of Standards and Technology, 325 Broadway, Boulder, CO 80305, USA
| | - T. Gerrits
- National Institute of Standards and Technology, 325 Broadway, Boulder, CO 80305, USA
| | - A. Lita
- National Institute of Standards and Technology, 325 Broadway, Boulder, CO 80305, USA
| | - W. S. Kolthammer
- Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, UK
| | - A. Eckstein
- Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, UK
| | - I. A. Walmsley
- Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, UK
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41
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Lee M, Friebe K, Fioretto DA, Schüppert K, Ong FR, Plankensteiner D, Torggler V, Ritsch H, Blatt R, Northup TE. Ion-Based Quantum Sensor for Optical Cavity Photon Numbers. PHYSICAL REVIEW LETTERS 2019; 122:153603. [PMID: 31050508 DOI: 10.1103/physrevlett.122.153603] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Indexed: 06/09/2023]
Abstract
We dispersively couple a single trapped ion to an optical cavity to extract information about the cavity photon-number distribution in a nondestructive way. The photon-number-dependent ac Stark shift experienced by the ion is measured via Ramsey spectroscopy. We use these measurements first to obtain the ion-cavity interaction strength. Next, we reconstruct the cavity photon-number distribution for coherent states and for a state with mixed thermal-coherent statistics, finding overlaps above 99% with the calibrated states.
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Affiliation(s)
- Moonjoo Lee
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - Konstantin Friebe
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - Dario A Fioretto
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - Klemens Schüppert
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - Florian R Ong
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - David Plankensteiner
- Institut für Theoretische Physik, Universität Innsbruck, Technikerstraße 21 a, 6020 Innsbruck, Austria
| | - Valentin Torggler
- Institut für Theoretische Physik, Universität Innsbruck, Technikerstraße 21 a, 6020 Innsbruck, Austria
| | - Helmut Ritsch
- Institut für Theoretische Physik, Universität Innsbruck, Technikerstraße 21 a, 6020 Innsbruck, Austria
| | - Rainer Blatt
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
- Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der Wissenschaften, Technikerstraße 21a, 6020 Innsbruck, Austria
| | - Tracy E Northup
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
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42
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Wang G, Xiao R, Shen HZ, Sun C, Xue K. Simulating Anisotropic quantum Rabi model via frequency modulation. Sci Rep 2019; 9:4569. [PMID: 30872697 PMCID: PMC6418198 DOI: 10.1038/s41598-019-40899-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 02/25/2019] [Indexed: 11/09/2022] Open
Abstract
Anisotropic quantum Rabi model is a generalization of quantum Rabi model, which allows its rotating and counter-rotating terms to have two different coupling constants. It provides us with a fundamental model to understand various physical features concerning quantum optics, solid-state physics, and mesoscopic physics. In this paper, we propose an experimental feasible scheme to implement anisotropic quantum Rabi model in a circuit quantum electrodynamics system via periodic frequency modulation. An effective Hamiltonian describing the tunable anisotropic quantum Rabi model can be derived from a qubit-resonator coupling system modulated by two periodic driving fields. All effective parameters of the simulated system can be adjusted by tuning the initial phases, the frequencies and the amplitudes of the driving fields. We show that the periodic driving is able to drive a coupled system in dispersive regime to ultrastrong coupling regime, and even deep-strong coupling regime. The derived effective Hamiltonian allows us to obtain pure rotating term and counter-rotating term. Numerical simulation shows that such effective Hamiltonian is valid in ultrastrong coupling regime, and stronger coupling regime. Moreover, our scheme can be generalized to the multi-qubit case. We also give some applications of the simulated system to the Schrödinger cat states and quantum gate generalization. The presented proposal will pave a way to further study the stronger anisotropic Rabi model whose coupling strength is far away from ultrastrong coupling and deep-strong coupling regimes in quantum optics.
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Affiliation(s)
- Gangcheng Wang
- Center for Quantum Sciences and School of Physics, Northeast Normal University, Changchun, 130024, China.
| | - Ruoqi Xiao
- Center for Quantum Sciences and School of Physics, Northeast Normal University, Changchun, 130024, China
| | - H Z Shen
- Center for Quantum Sciences and School of Physics, Northeast Normal University, Changchun, 130024, China.
| | - Chunfang Sun
- Center for Quantum Sciences and School of Physics, Northeast Normal University, Changchun, 130024, China
| | - Kang Xue
- Center for Quantum Sciences and School of Physics, Northeast Normal University, Changchun, 130024, China.
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43
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Malekakhlagh M, Rodriguez AW. Quantum Rabi Model with Two-Photon Relaxation. PHYSICAL REVIEW LETTERS 2019; 122:043601. [PMID: 30768294 DOI: 10.1103/physrevlett.122.043601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Indexed: 06/09/2023]
Abstract
We study a cavity-QED setup consisting of a two-level system coupled to a single cavity mode with two-photon relaxation. The system dynamics is modeled via a Lindblad master equation consisting of the Rabi Hamiltonian and a two-photon dissipator. We show that an even-photon relaxation preserves the Z_{2} symmetry of the Rabi model, and provide a framework to study the corresponding non-Hermitian dynamics in the number-parity basis. We discuss the role of different terms in the two-photon dissipator and show how one can extend existing results for the closed Rabi spectrum to the open case. Furthermore, we characterize the role of the Z_{2} symmetry in the excitation-relaxation dynamics of the system as a function of light-matter coupling. Importantly, we observe that initial states with even-odd parity manifest qualitatively distinct transient and steady state behaviors, contrary to the Hermitian dynamics that is only sensitive to whether or not the initial state is parity invariant. Moreover, the parity-sensitive dynamical behavior is not a creature of ultrastrong coupling and is present even at weak coupling values.
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Affiliation(s)
- Moein Malekakhlagh
- Department of Electrical Engineering, Princeton University, New Jersey 08544, USA
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44
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Yan L, Su S, Hou Q, Yang W, Feng M. Macroscopically distinct superposition in a spin ensemble coupled to superconducting flux-qubits. OPTICS EXPRESS 2019; 27:377-390. [PMID: 30696125 DOI: 10.1364/oe.27.000377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 11/28/2018] [Indexed: 06/09/2023]
Abstract
Large optical nonlinearities can create fancy physics, such as big Schrödinger-cat states and quadrature squeezing. We present the possibility to practically generate macroscopic Schrödinger-cat states, based on a giant Kerr nonlinearity, in a diamond nitrogen-vacancy ensemble interacting with two coupled flux-qubits. The nonlinearity comes from a four-level N-type configuration formed by two coupled flux-qubits under the appropriately driving fields. We discuss the experimental feasibility in the presence of system dissipations using current laboratory technology and our scheme can be easily extended to other ensemble systems.
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45
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Giordani T, Polino E, Emiliani S, Suprano A, Innocenti L, Majury H, Marrucci L, Paternostro M, Ferraro A, Spagnolo N, Sciarrino F. Experimental Engineering of Arbitrary Qudit States with Discrete-Time Quantum Walks. PHYSICAL REVIEW LETTERS 2019; 122:020503. [PMID: 30720314 DOI: 10.1103/physrevlett.122.020503] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Indexed: 06/09/2023]
Abstract
The capability to generate and manipulate quantum states in high-dimensional Hilbert spaces is a crucial step for the development of quantum technologies, from quantum communication to quantum computation. One-dimensional quantum walk dynamics represents a valid tool in the task of engineering arbitrary quantum states. Here we affirm such potential in a linear-optics platform that realizes discrete-time quantum walks in the orbital angular momentum degree of freedom of photons. Different classes of relevant qudit states in a six-dimensional space are prepared and measured, confirming the feasibility of the protocol. Our results represent a further investigation of quantum walk dynamics in photonics platforms, paving the way for the use of such a quantum state-engineering toolbox for a large range of applications.
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Affiliation(s)
- Taira Giordani
- Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 5, I-00185 Roma, Italy
| | - Emanuele Polino
- Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 5, I-00185 Roma, Italy
| | - Sabrina Emiliani
- Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 5, I-00185 Roma, Italy
| | - Alessia Suprano
- Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 5, I-00185 Roma, Italy
| | - Luca Innocenti
- Centre for Theoretical Atomic, Molecular, and Optical Physics, School of Mathematics and Physics, Queen's University Belfast, BT7 1NN Belfast, United Kingdom
| | - Helena Majury
- Centre for Theoretical Atomic, Molecular, and Optical Physics, School of Mathematics and Physics, Queen's University Belfast, BT7 1NN Belfast, United Kingdom
| | - Lorenzo Marrucci
- Dipartimento di Fisica "Ettore Pancini", Università Federico II, Complesso Universitario di Monte Sant'Angelo, Via Cintia, 80126 Napoli, Italy
| | - Mauro Paternostro
- Centre for Theoretical Atomic, Molecular, and Optical Physics, School of Mathematics and Physics, Queen's University Belfast, BT7 1NN Belfast, United Kingdom
| | - Alessandro Ferraro
- Centre for Theoretical Atomic, Molecular, and Optical Physics, School of Mathematics and Physics, Queen's University Belfast, BT7 1NN Belfast, United Kingdom
| | - Nicolò Spagnolo
- Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 5, I-00185 Roma, Italy
| | - Fabio Sciarrino
- Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 5, I-00185 Roma, Italy
- Consiglio Nazionale delle Ricerche, Istituto dei sistemi Complessi (CNR-ISC), Via dei Taurini 19, 00185 Roma, Italy
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46
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Di Stefano O, Kockum AF, Ridolfo A, Savasta S, Nori F. Photodetection probability in quantum systems with arbitrarily strong light-matter interaction. Sci Rep 2018; 8:17825. [PMID: 30546126 PMCID: PMC6292927 DOI: 10.1038/s41598-018-36056-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 11/14/2018] [Indexed: 12/02/2022] Open
Abstract
Cavity-QED systems have recently reached a regime where the light-matter interaction strength amounts to a non-negligible fraction of the resonance frequencies of the bare subsystems. In this regime, it is known that the usual normal-order correlation functions for the cavity-photon operators fail to describe both the rate and the statistics of emitted photons. Following Glauber’s original approach, we derive a simple and general quantum theory of photodetection, valid for arbitrary light-matter interaction strengths. Our derivation uses Fermi’s golden rule, together with an expansion of system operators in the eigenbasis of the interacting light-matter system, to arrive at the correct photodetection probabilities. We consider both narrow- and wide-band photodetectors. Our description is also valid for point-like detectors placed inside the optical cavity. As an application, we propose a gedanken experiment confirming the virtual nature of the bare excitations that enrich the ground state of the quantum Rabi model.
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Affiliation(s)
- Omar Di Stefano
- Theoretical Quantum Physics Laboratory, RIKEN Cluster for Pioneering Research, Wako-shi, Saitama, 351-0198, Japan
| | - Anton Frisk Kockum
- Theoretical Quantum Physics Laboratory, RIKEN Cluster for Pioneering Research, Wako-shi, Saitama, 351-0198, Japan.,Wallenberg Centre for Quantum Technology, Department of Microtechnology and Nanoscience, Chalmers University of Technology, 412 96, Gothenburg, Sweden
| | - Alessandro Ridolfo
- Theoretical Quantum Physics Laboratory, RIKEN Cluster for Pioneering Research, Wako-shi, Saitama, 351-0198, Japan
| | - Salvatore Savasta
- Theoretical Quantum Physics Laboratory, RIKEN Cluster for Pioneering Research, Wako-shi, Saitama, 351-0198, Japan. .,MIFT - Dipartimento di Scienze Matematiche e Informatiche Scienze Fisiche e Scienze della Terra, Università di Messina, I-98166, Messina, Italy.
| | - Franco Nori
- Theoretical Quantum Physics Laboratory, RIKEN Cluster for Pioneering Research, Wako-shi, Saitama, 351-0198, Japan.,Physics Department, The University of Michigan, Ann Arbor, Michigan, 48109-1040, USA
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47
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Quantum control of surface acoustic-wave phonons. Nature 2018; 563:661-665. [DOI: 10.1038/s41586-018-0719-5] [Citation(s) in RCA: 184] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 09/10/2018] [Indexed: 11/08/2022]
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48
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Creation and control of multi-phonon Fock states in a bulk acoustic-wave resonator. Nature 2018; 563:666-670. [DOI: 10.1038/s41586-018-0717-7] [Citation(s) in RCA: 120] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 09/10/2018] [Indexed: 11/08/2022]
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49
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Ye B, Zheng ZF, Zhang Y, Yang CP. Circuit QED: single-step realization of a multiqubit controlled phase gate with one microwave photonic qubit simultaneously controlling n - 1 microwave photonic qubits. OPTICS EXPRESS 2018; 26:30689-30702. [PMID: 30469962 DOI: 10.1364/oe.26.030689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 10/25/2018] [Indexed: 06/09/2023]
Abstract
We present a novel method to realize a multi-target-qubit controlled phase gate with one microwave photonic qubit simultaneously controlling n - 1 target microwave photonic qubits. This gate is implemented with n microwave cavities coupled to a superconducting flux qutrit. Each cavity hosts a microwave photonic qubit, whose two logic states are represented by the vacuum state and the single photon state of a single cavity mode, respectively. During the gate operation, the qutrit remains in the ground state and thus decoherence from the qutrit is greatly suppressed. This proposal requires only a single-step operation and thus the gate implementation is quite simple. The gate operation time is independent of the number of the qubits. In addition, this proposal does not need applying classical pulse or any measurement. Numerical simulations demonstrate that high-fidelity realization of a controlled phase gate with one microwave photonic qubit simultaneously controlling two target microwave photonic qubits is feasible with current circuit QED technology. The proposal is quite general and can be applied to implement the proposed gate in a wide range of physical systems, such as multiple microwave or optical cavities coupled to a natural or artificial Λ-type three-level atom.
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50
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Viennot JJ, Ma X, Lehnert KW. Phonon-Number-Sensitive Electromechanics. PHYSICAL REVIEW LETTERS 2018; 121:183601. [PMID: 30444407 DOI: 10.1103/physrevlett.121.183601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Indexed: 06/09/2023]
Abstract
We use the strong intrinsic nonlinearity of a microwave superconducting qubit with a 4 GHz transition frequency to directly detect and control the energy of a micromechanical oscillator vibrating at 25 MHz. The qubit and the oscillator are coupled electrostatically at a rate of approximately 2π×22 MHz. In this far off-resonant regime, the qubit frequency is shifted by 0.52 MHz per oscillator phonon, or about 14% of the 3.7 MHz qubit linewidth. The qubit behaves as a vibrational energy detector and from its line shape we extract the phonon number distribution of the oscillator. We manipulate this distribution by driving number state sensitive sideband transitions and creating profoundly nonthermal states. Finally, by driving the lower frequency sideband transition, we cool the oscillator and increase its ground state population up to 0.48±0.13, close to a factor of 8 above its value at thermal equilibrium. These results demonstrate a new class of electromechanics experiments that are a promising strategy for quantum nondemolition measurements and nonclassical state preparation.
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Affiliation(s)
- J J Viennot
- JILA, National Institute of Standards and Technology and the University of Colorado, Boulder, Colorado 80309, USA and Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - X Ma
- JILA, National Institute of Standards and Technology and the University of Colorado, Boulder, Colorado 80309, USA and Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - K W Lehnert
- JILA, National Institute of Standards and Technology and the University of Colorado, Boulder, Colorado 80309, USA and Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
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