1
|
Li S, Ni Z, Zhang L, Cai Y, Mai J, Wen S, Zheng P, Deng X, Liu S, Xu Y, Yu D. Autonomous Stabilization of Fock States in an Oscillator against Multiphoton Losses. PHYSICAL REVIEW LETTERS 2024; 132:203602. [PMID: 38829095 DOI: 10.1103/physrevlett.132.203602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 04/23/2024] [Indexed: 06/05/2024]
Abstract
Fock states with a well-defined number of photons in an oscillator have shown a wide range of applications in quantum information science. Nonetheless, their usefulness has been marred by single and multiphoton losses due to unavoidable environment-induced dissipation. Though several dissipation engineering methods have been developed to counteract the leading single-photon-loss error, averting multiple-photon losses remains elusive. Here, we experimentally demonstrate a dissipation engineering method that autonomously stabilizes multiphoton Fock states against losses of multiple photons using a cascaded selective photon-addition operation in a superconducting quantum circuit. Through measuring the photon-number populations and Wigner tomography of the oscillator states, we observe a prolonged preservation of nonclassical Wigner negativities for the stabilized Fock states |N⟩ with N=1, 2, 3 for a duration of about 10 ms. Furthermore, the dissipation engineering method demonstrated here also facilitates the implementation of a nonunitary operation for resetting a binomially encoded logical qubit. These results highlight potential applications in error-correctable quantum information processing against multiple-photon-loss errors.
Collapse
Affiliation(s)
- Sai Li
- Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- International Quantum Academy, Shenzhen 518048, China
- Guangdong Provincial Key Laboratory of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Zhongchu Ni
- Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- International Quantum Academy, Shenzhen 518048, China
- Guangdong Provincial Key Laboratory of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
| | - Libo Zhang
- Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- International Quantum Academy, Shenzhen 518048, China
- Guangdong Provincial Key Laboratory of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Yanyan Cai
- Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- International Quantum Academy, Shenzhen 518048, China
- Guangdong Provincial Key Laboratory of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Jiasheng Mai
- Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- International Quantum Academy, Shenzhen 518048, China
- Guangdong Provincial Key Laboratory of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Shengcheng Wen
- Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- International Quantum Academy, Shenzhen 518048, China
- Guangdong Provincial Key Laboratory of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Pan Zheng
- Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- International Quantum Academy, Shenzhen 518048, China
- Guangdong Provincial Key Laboratory of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Xiaowei Deng
- Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- International Quantum Academy, Shenzhen 518048, China
- Guangdong Provincial Key Laboratory of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Song Liu
- Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- International Quantum Academy, Shenzhen 518048, China
- Guangdong Provincial Key Laboratory of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- Shenzhen Branch, Hefei National Laboratory, Shenzhen 518048, China
| | - Yuan Xu
- Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- International Quantum Academy, Shenzhen 518048, China
- Guangdong Provincial Key Laboratory of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- Shenzhen Branch, Hefei National Laboratory, Shenzhen 518048, China
| | - Dapeng Yu
- Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- International Quantum Academy, Shenzhen 518048, China
- Guangdong Provincial Key Laboratory of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
- Shenzhen Branch, Hefei National Laboratory, Shenzhen 518048, China
| |
Collapse
|
2
|
Bærentsen C, Fedorov SA, Østfeldt C, Balabas MV, Zeuthen E, Polzik ES. Squeezed light from an oscillator measured at the rate of oscillation. Nat Commun 2024; 15:4146. [PMID: 38755123 PMCID: PMC11099115 DOI: 10.1038/s41467-024-47906-0] [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: 09/06/2023] [Accepted: 04/15/2024] [Indexed: 05/18/2024] Open
Abstract
Sufficiently fast continuous measurements of the position of an oscillator approach measurements projective on position eigenstates. We evidence the transition into the projective regime for a spin oscillator within an ensemble of 2 × 1010 room-temperature atoms by observing correlations between the quadratures of the meter light field. These correlations squeeze the fluctuations of one light quadrature below the vacuum level. When the measurement is slower than the oscillation, we generate 11 . 5 - 1.5 + 2.5 dB and detect 8 . 5 - 0.1 + 0.1 dB of squeezing in a tunable band that is a fraction of the resonance frequency. When the measurement is as fast as the oscillation, we detect 4.7 dB of squeezing that spans more than one decade of frequencies below the resonance. Our results demonstrate a new regime of continuous quantum measurements on material oscillators, and set a new benchmark for the performance of a linear quantum sensor.
Collapse
Affiliation(s)
| | - Sergey A Fedorov
- Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark.
| | | | | | - Emil Zeuthen
- Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Eugene S Polzik
- Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark.
| |
Collapse
|
3
|
Liu ZQ, Liu L, Meng ZZ, Tan L, Liu WM. Simultaneously enhanced magnomechanical cooling and entanglement assisted by an auxiliary microwave cavity. OPTICS EXPRESS 2024; 32:722-741. [PMID: 38175094 DOI: 10.1364/oe.504580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 11/17/2023] [Indexed: 01/05/2024]
Abstract
We propose a mechanism to simultaneously enhance quantum cooling and entanglement via coupling an auxiliary microwave cavity to a magnomechanical cavity. The auxiliary cavity acts as a dissipative cold reservoir that can efficiently cool multiple localized modes in the primary system via beam-splitter interactions, which enables us to obtain strong quantum cooling and entanglement. We analyze the stability of the system and determine the optimal parameter regime for cooling and entanglement under the auxiliary-microwave-cavity-assisted (AMCA) scheme. The maximum cooling enhancement rate of the magnon mode can reach 98.53%, which clearly reveals that the magnomechanical cooling is significantly improved in the presence of the AMCA. More importantly, the dual-mode entanglement of the system can also be significantly enhanced by AMCA in the full parameter region, where the initial magnon-phonon entanglement can be maximally enhanced by a factor of about 11. Another important result of the AMCA is that it also increases the robustness of the entanglement against temperature. Our approach provides a promising platform for the experimental realization of entanglement and quantum information processing based on cavity magnomechanics.
Collapse
|
4
|
Jia J, Novikov V, Brasil TB, Zeuthen E, Müller JH, Polzik ES. Acoustic frequency atomic spin oscillator in the quantum regime. Nat Commun 2023; 14:6396. [PMID: 37828042 PMCID: PMC10570288 DOI: 10.1038/s41467-023-42059-y] [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: 03/16/2023] [Accepted: 09/28/2023] [Indexed: 10/14/2023] Open
Abstract
Quantum noise reduction and entanglement-enhanced sensing in the acoustic frequency range is an outstanding challenge relevant for a number of applications including magnetometry and broadband noise reduction in gravitational wave detectors. Here we experimentally demonstrate quantum behavior of a macroscopic atomic spin oscillator in the acoustic frequency range. Quantum back-action of the spin measurement, ponderomotive squeezing of light, and virtual spring softening are observed at oscillation frequencies down to the sub-kHz range. Quantum noise sources characteristic of spin oscillators operating in the near-DC frequency range are identified and means for their mitigation are presented.
Collapse
Affiliation(s)
- Jun Jia
- Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Valeriy Novikov
- Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
- Russian Quantum Center, Skolkovo, Moscow, Russia
| | | | - Emil Zeuthen
- Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | | | - Eugene S Polzik
- Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark.
| |
Collapse
|
5
|
Luo S, Shen K, Wang F. Dephasing-assisted preparation of asymmetric steering in coupled quantum wells. OPTICS EXPRESS 2023; 31:30767-30782. [PMID: 37710613 DOI: 10.1364/oe.499410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 08/19/2023] [Indexed: 09/16/2023]
Abstract
It is shown that the dephasing rates are usually harmful for quantum correlations in various systems. Nevertheless, we explore that the dephasing rates in the coupled quantum wells (QWs), as a major contribution of the decay processes, can assist to generate one-way Einstein-Podolsky-Rosen (EPR) steering. By applying two strong fields to drive two dipole-allowed transitions while the other transitions are coupled with two quantized modes, the asymmetric EPR steering is possible to obtain at steady state through a single-pathway dissipation in the three-well system. According to dressed-state and Bogoliubov mode transformation, we find that the dephasing rates play a role in modifying the dressed-state populations and the dissipation rate through multiple quantum interference mechanisms. The positive effect of the dephasing rates from a nanostructure on quantum correlation is expected to find potential applications in quantum information processing.
Collapse
|
6
|
Behrle T, Nguyen TL, Reiter F, Baur D, de Neeve B, Stadler M, Marinelli M, Lancellotti F, Yelin SF, Home JP. Phonon Laser in the Quantum Regime. PHYSICAL REVIEW LETTERS 2023; 131:043605. [PMID: 37566845 DOI: 10.1103/physrevlett.131.043605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 05/30/2023] [Indexed: 08/13/2023]
Abstract
We demonstrate a trapped-ion system with two competing dissipation channels, implemented independently on two ion species cotrapped in a Paul trap. By controlling coherent spin-oscillator couplings and optical pumping rates we explore the phase diagram of this system, which exhibits a regime analogous to that of a (phonon) laser but operates close to the quantum ground state with an average phonon number of n[over ¯]<10. We demonstrate phase locking of the oscillator to an additional resonant drive, and also observe the phase diffusion of the resulting state under dissipation by reconstructing the quantum state from a measurement of the characteristic function.
Collapse
Affiliation(s)
- T Behrle
- Institute for Quantum Electronics, ETH Zürich, Otto-Stern-Weg 1, 8093 Zürich, Switzerland
| | - T L Nguyen
- Institute for Quantum Electronics, ETH Zürich, Otto-Stern-Weg 1, 8093 Zürich, Switzerland
| | - F Reiter
- Institute for Quantum Electronics, ETH Zürich, Otto-Stern-Weg 1, 8093 Zürich, Switzerland
- Harvard University, 17 Oxford Street, Cambridge, Massachusetts 02138, USA
| | - D Baur
- Institute for Quantum Electronics, ETH Zürich, Otto-Stern-Weg 1, 8093 Zürich, Switzerland
| | - B de Neeve
- Institute for Quantum Electronics, ETH Zürich, Otto-Stern-Weg 1, 8093 Zürich, Switzerland
| | - M Stadler
- Institute for Quantum Electronics, ETH Zürich, Otto-Stern-Weg 1, 8093 Zürich, Switzerland
| | - M Marinelli
- Institute for Quantum Electronics, ETH Zürich, Otto-Stern-Weg 1, 8093 Zürich, Switzerland
| | - F Lancellotti
- Institute for Quantum Electronics, ETH Zürich, Otto-Stern-Weg 1, 8093 Zürich, Switzerland
| | - S F Yelin
- Harvard University, 17 Oxford Street, Cambridge, Massachusetts 02138, USA
| | - J P Home
- Institute for Quantum Electronics, ETH Zürich, Otto-Stern-Weg 1, 8093 Zürich, Switzerland
- Quantum Center, ETH Zürich, 8093 Zürich, Switzerland
| |
Collapse
|
7
|
Saha AK, Ray DS, Deb B. Phase diffusion and fluctuations in a dissipative Bose-Josephson junction. Phys Rev E 2023; 107:034141. [PMID: 37073026 DOI: 10.1103/physreve.107.034141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 03/16/2023] [Indexed: 04/20/2023]
Abstract
We analyze the phase diffusion, quantum fluctuations and their spectral features of a one-dimensional Bose-Josephson junction (BJJ) nonlinearly coupled to a bosonic heat bath. The phase diffusion is considered by taking into account of random modulations of the BJJ modes causing a phase loss of initial coherence between the ground and excited states, whereby the frequency modulation is incorporated in the system-reservoir Hamiltonian by an interaction term linear in bath operators but nonlinear in system (BJJ) operators. We examine the dependence of the phase diffusion coefficient on the on-site interaction and temperature in the zero- and π-phase modes and demonstrate its phase transition-like behavior between the Josephson oscillation and the macroscopic quantum self-trapping (MQST) regimes in the π-phase mode. Based on the thermal canonical Wigner distribution, which is the equilibrium solution of the associated quantum Langevin equation for phase, coherence factor is calculated to study phase diffusion for the zero- and π-phase modes. We investigate the quantum fluctuations of the relative phase and population imbalance in terms of fluctuation spectra which capture an interesting shift in Josephson frequency induced by frequency fluctuation due to nonlinear system-reservoir coupling, as well as the on-site interaction-induced splitting in the weak dissipative regime.
Collapse
Affiliation(s)
- Abhik Kumar Saha
- School of Physical Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
| | - Deb Shankar Ray
- School of Chemical Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
| | - Bimalendu Deb
- School of Physical Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
| |
Collapse
|
8
|
Ma L, Lei X, Cheng J, Yan Z, Jia X. Deterministic manipulation of steering between distant quantum network nodes. OPTICS EXPRESS 2023; 31:8257-8266. [PMID: 36859941 DOI: 10.1364/oe.479182] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 02/03/2023] [Indexed: 06/18/2023]
Abstract
Multipartite Einstein-Podolsky-Rosen (EPR) steering is a key resource in a quantum network. Although EPR steering between spatially separated regions of ultracold atomic systems has been observed, deterministic manipulation of steering between distant quantum network nodes is required for a secure quantum communication network. Here, we propose a feasible scheme to deterministically generate, store, and manipulate one-way EPR steering between distant atomic cells by a cavity-enhanced quantum memory approach. While optical cavities effectively suppress the unavoidable noises in electromagnetically induced transparency, three atomic cells are in a strong Greenberger-Horne-Zeilinger state by faithfully storing three spatially separated entangled optical modes. In this way, the strong quantum correlation of atomic cells guarantees one-to-two node EPR steering is achieved, and can perserve the stored EPR steering in these quantum nodes. Furthermore, the steerability can be actively manipulated by the temperature of the atomic cell. This scheme provides the direct reference for experimental implementation for one-way multipartite steerable states, which enables an asymmetric quantum network protocol.
Collapse
|
9
|
Hayashida K, Makihara T, Marquez Peraca N, Fallas Padilla D, Pu H, Kono J, Bamba M. Perfect intrinsic squeezing at the superradiant phase transition critical point. Sci Rep 2023; 13:2526. [PMID: 36781905 PMCID: PMC9925797 DOI: 10.1038/s41598-023-29202-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 01/31/2023] [Indexed: 02/15/2023] Open
Abstract
Some of the most exotic properties of the quantum vacuum are predicted in ultrastrongly coupled photon-atom systems; one such property is quantum squeezing leading to suppressed quantum fluctuations of photons and atoms. This squeezing is unique because (1) it is realized in the ground state of the system and does not require external driving, and (2) the squeezing can be perfect in the sense that quantum fluctuations of certain observables are completely suppressed. Specifically, we investigate the ground state of the Dicke model, which describes atoms collectively coupled to a single photonic mode, and we found that the photon-atom fluctuation vanishes at the onset of the superradiant phase transition in the thermodynamic limit of an infinite number of atoms. Moreover, when a finite number of atoms is considered, the variance of the fluctuation around the critical point asymptotically converges to zero, as the number of atoms is increased. In contrast to the squeezed states of flying photons obtained using standard generation protocols with external driving, the squeezing obtained in the ground state of the ultrastrongly coupled photon-atom systems is resilient against unpredictable noise.
Collapse
Affiliation(s)
- Kenji Hayashida
- grid.21940.3e0000 0004 1936 8278Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005 USA ,grid.39158.360000 0001 2173 7691Division of Applied Physics, Graduate School and Faculty of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628 Japan
| | - Takuma Makihara
- grid.21940.3e0000 0004 1936 8278Department of Physics and Astronomy, Rice University, Houston, TX 77005 USA
| | - Nicolas Marquez Peraca
- grid.21940.3e0000 0004 1936 8278Department of Physics and Astronomy, Rice University, Houston, TX 77005 USA
| | - Diego Fallas Padilla
- grid.21940.3e0000 0004 1936 8278Department of Physics and Astronomy, Rice University, Houston, TX 77005 USA
| | - Han Pu
- grid.21940.3e0000 0004 1936 8278Department of Physics and Astronomy, Rice University, Houston, TX 77005 USA
| | - Junichiro Kono
- grid.21940.3e0000 0004 1936 8278Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005 USA ,grid.21940.3e0000 0004 1936 8278Department of Physics and Astronomy, Rice University, Houston, TX 77005 USA ,grid.21940.3e0000 0004 1936 8278Department of Materials Science and Nano Engineering, Rice University, Houston, TX 77005 USA
| | - Motoaki Bamba
- Department of Physics I, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto, 606-8502, Japan. .,The Hakubi Center for Advanced Research, Kyoto University, Kyoto, 606-8501, Japan. .,PRESTO, Japan Science and Technology Agency, Kawaguchi, 332-0012, Japan.
| |
Collapse
|
10
|
Zou CJ, Li Y, Xu JK, You JB, Png CE, Yang WL. Geometrical Bounds on Irreversibility in Squeezed Thermal Bath. ENTROPY (BASEL, SWITZERLAND) 2023; 25:128. [PMID: 36673269 PMCID: PMC9858152 DOI: 10.3390/e25010128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 12/23/2022] [Accepted: 01/05/2023] [Indexed: 06/17/2023]
Abstract
Irreversible entropy production (IEP) plays an important role in quantum thermodynamic processes. Here, we investigate the geometrical bounds of IEP in nonequilibrium thermodynamics by exemplifying a system coupled to a squeezed thermal bath subject to dissipation and dephasing, respectively. We find that the geometrical bounds of the IEP always shift in a contrary way under dissipation and dephasing, where the lower and upper bounds turning to be tighter occur in the situation of dephasing and dissipation, respectively. However, either under dissipation or under dephasing, we may reduce both the critical time of the IEP itself and the critical time of the bounds for reaching an equilibrium by harvesting the benefits of squeezing effects in which the values of the IEP, quantifying the degree of thermodynamic irreversibility, also become smaller. Therefore, due to the nonequilibrium nature of the squeezed thermal bath, the system-bath interaction energy has a prominent impact on the IEP, leading to tightness of its bounds. Our results are not contradictory with the second law of thermodynamics by involving squeezing of the bath as an available resource, which can improve the performance of quantum thermodynamic devices.
Collapse
Affiliation(s)
- Chen-Juan Zou
- Research Center of Nonlinear Science, School of Mathematical and Physical Science, Wuhan Textile University, Wuhan 430200, China
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Yue Li
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Jia-Kun Xu
- Research Center of Nonlinear Science, School of Mathematical and Physical Science, Wuhan Textile University, Wuhan 430200, China
| | - Jia-Bin You
- Institute of High Performance Computing, Agency for Science, Technology, and Research (A*STAR), 1 Fusionopolis Way, #16-16 Connexis, Singapore 138632, Singapore
| | - Ching Eng Png
- Institute of High Performance Computing, Agency for Science, Technology, and Research (A*STAR), 1 Fusionopolis Way, #16-16 Connexis, Singapore 138632, Singapore
| | - Wan-Li Yang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China
| |
Collapse
|
11
|
Hybrid classical-quantum machine learning based on dissipative two-qubit channels. Sci Rep 2022; 12:20440. [DOI: 10.1038/s41598-022-24346-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 11/14/2022] [Indexed: 11/29/2022] Open
Abstract
AbstractAlthough the environmental effects, i.e., dissipation and decoherence seem to be the strongest adversaries in the quantum information realm, here, we address how dissipation can be harnessed for quantum state preparation and universal quantum computation. In this line, we propose a realistic scheme for hybrid classical-quantum neural networks based on dissipative two-qubit channels. In particular, we design a variational quantum circuit consisting of a set of universal quantum gates. We encode classical information in the initial states of a two-qubit system interacting with a global environment. This composite system plays the role of a dissipative quantum channel (DQC). A pooling layer concatenates the output states of the DQCs resulting in the outcome of the circuit. Both the DCQs and the pooling layer provide superposition and entanglement which are the key ingredients of any universal quantum computation protocol. Finally, we investigate the capability and adaptability of this model by doing some machine learning tasks. It is reasonable to postulate that a quantum computer based on DQCs may outperform a classical computer because, in contrast to the latter, the former is capable of producing atypical patterns through non-classical phenomena.
Collapse
|
12
|
Aiello G, Féchant M, Morvan A, Basset J, Aprili M, Gabelli J, Estève J. Quantum bath engineering of a high impedance microwave mode through quasiparticle tunneling. Nat Commun 2022; 13:7146. [PMID: 36414638 PMCID: PMC9681747 DOI: 10.1038/s41467-022-34762-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 11/04/2022] [Indexed: 11/24/2022] Open
Abstract
In microwave quantum optics, dissipation usually corresponds to quantum jumps, where photons are lost one by one. Here we demonstrate a new approach to dissipation engineering. By coupling a high impedance microwave resonator to a tunnel junction, we use the photoassisted tunneling of quasiparticles as a tunable dissipative process. We are able to adjust the minimum number of lost photons per tunneling event to be one, two or more, through a dc voltage. Consequently, different Fock states of the resonator experience different loss processes. Causality then implies that each state experiences a different energy (Lamb) shift, as confirmed experimentally. This photoassisted tunneling process is analogous to a photoelectric effect, which requires a quantum description of light to be quantitatively understood. This work opens up new possibilities for quantum state manipulation in superconducting circuits, which do not rely on the Josephson effect.
Collapse
Affiliation(s)
- Gianluca Aiello
- Laboratoire de Physique des Solides, CNRS, Université Paris Saclay, Orsay, France
| | - Mathieu Féchant
- Laboratoire de Physique des Solides, CNRS, Université Paris Saclay, Orsay, France
| | - Alexis Morvan
- Laboratoire de Physique des Solides, CNRS, Université Paris Saclay, Orsay, France
| | - Julien Basset
- Laboratoire de Physique des Solides, CNRS, Université Paris Saclay, Orsay, France
| | - Marco Aprili
- Laboratoire de Physique des Solides, CNRS, Université Paris Saclay, Orsay, France
| | - Julien Gabelli
- Laboratoire de Physique des Solides, CNRS, Université Paris Saclay, Orsay, France
| | - Jérôme Estève
- Laboratoire de Physique des Solides, CNRS, Université Paris Saclay, Orsay, France.
| |
Collapse
|
13
|
Ren ZQ, Feng CR, Xiang ZL. Deterministic generation of entanglement states between Silicon-Vacancy centers via acoustic modes. OPTICS EXPRESS 2022; 30:41685-41697. [PMID: 36366639 DOI: 10.1364/oe.468293] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 10/11/2022] [Indexed: 06/16/2023]
Abstract
We propose a scheme to entangle Silicon-Vacancy (SiV) centers embedded in a diamond acoustic waveguide. These SiV centers interact with acoustic modes of the waveguide via strain-induced coupling. Through Morris-Shore transformation, the Hilbert space of this hybrid quantum system can be factorized into a closed subspace in which we can deterministically realize the symmetrical Dicke states between distant SiV centers with high fidelity. In addition, the generation of entangled Dicke states can be controlled by manipulating the strength and frequency of the driving field applied on SiV centers. This protocol provides a promising way to prepare multipartite entanglement in spin-phonon hybrid systems and could have broad applications for future quantum technologies.
Collapse
|
14
|
Trade off-free entanglement stabilization in a superconducting qutrit-qubit system. Nat Commun 2022; 13:3994. [PMID: 35810169 PMCID: PMC9271051 DOI: 10.1038/s41467-022-31638-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 06/28/2022] [Indexed: 11/09/2022] Open
Abstract
Quantum reservoir engineering is a powerful framework for autonomous quantum state preparation and error correction. However, traditional approaches to reservoir engineering are hindered by unavoidable coherent leakage out of the target state, which imposes an inherent trade off between achievable steady-state state fidelity and stabilization rate. In this work we demonstrate a protocol that achieves trade off-free Bell state stabilization in a qutrit-qubit system realized on a circuit-QED platform. We accomplish this by creating a purely dissipative channel for population transfer into the target state, mediated by strong parametric interactions coupling the second-excited state of a superconducting transmon and the engineered bath resonator. Our scheme achieves a state preparation fidelity of 84% with a stabilization time constant of 339 ns, leading to a 54 ns error-time product in a solid-state quantum information platform.
Collapse
|
15
|
Singh VP, Weimer H. Driven-Dissipative Criticality within the Discrete Truncated Wigner Approximation. PHYSICAL REVIEW LETTERS 2022; 128:200602. [PMID: 35657854 DOI: 10.1103/physrevlett.128.200602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 04/14/2022] [Indexed: 06/15/2023]
Abstract
We present an approach to the numerical simulation of open quantum many-body systems based on the semiclassical framework of the discrete truncated Wigner approximation. We establish a quantum jump formalism to integrate the quantum master equation describing the dynamics of the system, which we find to be exact in both the noninteracting limit and the limit where the system is described by classical rate equations. We apply our method to simulation of the paradigmatic dissipative Ising model, where we are able to capture the critical fluctuations of the system beyond the level of mean-field theory.
Collapse
Affiliation(s)
- Vijay Pal Singh
- Institut für Theoretische Physik, Leibniz Universität Hannover, Appelstraße 2, 30167 Hannover, Germany
- Zentrum für Optische Quantentechnologien and Institut für Laserphysik, Universität Hamburg, 22761 Hamburg, Germany
| | - Hendrik Weimer
- Institut für Theoretische Physik, Leibniz Universität Hannover, Appelstraße 2, 30167 Hannover, Germany
| |
Collapse
|
16
|
Cole DC, Erickson SD, Zarantonello G, Horn KP, Hou PY, Wu JJ, Slichter DH, Reiter F, Koch CP, Leibfried D. Resource-Efficient Dissipative Entanglement of Two Trapped-Ion Qubits. PHYSICAL REVIEW LETTERS 2022; 128:080502. [PMID: 35275690 DOI: 10.1103/physrevlett.128.080502] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 12/02/2021] [Indexed: 06/14/2023]
Abstract
We demonstrate a simplified method for dissipative generation of an entangled state of two trapped-ion qubits. Our implementation produces its target state faster and with higher fidelity than previous demonstrations of dissipative entanglement generation and eliminates the need for auxiliary ions. The entangled singlet state is generated in ∼7 ms with a fidelity of 0.949(4). The dominant source of infidelity is photon scattering. We discuss this error source and strategies for its mitigation.
Collapse
Affiliation(s)
- 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
| | - Giorgio Zarantonello
- National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA
- Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - Karl P Horn
- Theoretische Physik, Universität Kassel, Heinrich-Plett-Straße 40, 34132 Kassel, Germany
| | - 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
| | - 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
| | - Daniel H Slichter
- National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA
| | - Florentin Reiter
- Institute for Quantum Electronics, ETH Zürich, Otto-Stern-Weg 1, 8093 Zürich, Switzerland
| | - Christiane P Koch
- Theoretische Physik, Universität Kassel, Heinrich-Plett-Straße 40, 34132 Kassel, Germany
- Dahlem Center for Complex Quantum Systems and Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Dietrich Leibfried
- National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA
| |
Collapse
|
17
|
Malinowski M, Zhang C, Negnevitsky V, Rojkov I, Reiter F, Nguyen TL, Stadler M, Kienzler D, Mehta KK, Home JP. Generation of a Maximally Entangled State Using Collective Optical Pumping. PHYSICAL REVIEW LETTERS 2022; 128:080503. [PMID: 35275689 DOI: 10.1103/physrevlett.128.080503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 12/10/2021] [Accepted: 01/11/2022] [Indexed: 06/14/2023]
Abstract
We propose and implement a novel scheme for dissipatively pumping two qubits into a singlet Bell state. The method relies on a process of collective optical pumping to an excited level, to which all states apart from the singlet are coupled. We apply the method to deterministically entangle two trapped ^{40}Ca^{+} ions. Within 16 pumping cycles, an initially separable state is transformed into one with 83(1)% singlet fidelity, and states with initial fidelity of ⪆70% converge onto a fidelity of 93(1)%. We theoretically analyze the performance and error susceptibility of the scheme and find it to be insensitive to a large class of experimentally relevant noise sources.
Collapse
Affiliation(s)
- M Malinowski
- Institute for Quantum Electronics, ETH Zürich, 8093 Zürich, Switzerland
| | - C Zhang
- Institute for Quantum Electronics, ETH Zürich, 8093 Zürich, Switzerland
| | - V Negnevitsky
- Institute for Quantum Electronics, ETH Zürich, 8093 Zürich, Switzerland
| | - I Rojkov
- Institute for Quantum Electronics, ETH Zürich, 8093 Zürich, Switzerland
| | - F Reiter
- Institute for Quantum Electronics, ETH Zürich, 8093 Zürich, Switzerland
| | - T-L Nguyen
- Institute for Quantum Electronics, ETH Zürich, 8093 Zürich, Switzerland
| | - M Stadler
- Institute for Quantum Electronics, ETH Zürich, 8093 Zürich, Switzerland
| | - D Kienzler
- Institute for Quantum Electronics, ETH Zürich, 8093 Zürich, Switzerland
| | - K K Mehta
- Institute for Quantum Electronics, ETH Zürich, 8093 Zürich, Switzerland
| | - J P Home
- Institute for Quantum Electronics, ETH Zürich, 8093 Zürich, Switzerland
- Quantum center, ETH Zürich, 8093 Zürich, Switzerland
| |
Collapse
|
18
|
Planella G, Cenni MFB, Acín A, Mehboudi M. Bath-Induced Correlations Enhance Thermometry Precision at Low Temperatures. PHYSICAL REVIEW LETTERS 2022; 128:040502. [PMID: 35148153 DOI: 10.1103/physrevlett.128.040502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 12/22/2021] [Indexed: 06/14/2023]
Abstract
We study the role of bath-induced correlations in temperature estimation of cold bosonic baths. Our protocol includes multiple probes, that are not interacting, nor are they initially correlated to each other. They interact with a bosonic sample and reach a nonthermal steady state, which is measured to estimate the temperature of the sample. It is well known that in the steady state such noninteracting probes may get correlated to each other and even entangled. Nonetheless, the impact of these correlations in metrology has not been deeply investigated yet. Here, we examine their role for thermometry of cold bosonic gases and show that, although being classical, bath-induced correlations can lead to significant enhancement of precision for thermometry. The improvement is especially important at low temperatures, where attaining high precision thermometry is particularly demanding. The proposed thermometry scheme does not require any precise dynamical control of the probes and tuning the parameters and is robust to noise in initial preparation, as it is built upon the steady state generated by the natural dissipative dynamics of the system. Therefore, our results put forward new possibilities in thermometry at low temperatures, of relevance, for instance, in cold gases and Bose-Einstein condensates.
Collapse
Affiliation(s)
- Guim Planella
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
- Facultat de Física, Universitat de Barcelona, 08028 Barcelona, Spain
- Institute for Theoretical Physics, Utrecht University, 3584 CS Utrecht, Netherlands
| | - Marina F B Cenni
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
| | - Antonio Acín
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
- ICREA-Institució Catalana de Recerca i Estudis Avançats, 08010 Barcelona, Spain
| | - Mohammad Mehboudi
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
- Max-Planck-Institut für Quantenoptik, D-85748 Garching, Germany
- Département de Physique Appliquée, Université de Genève, 1211 Genève, Switzerland
| |
Collapse
|
19
|
Bai SY, An JH. Generating Stable Spin Squeezing by Squeezed-Reservoir Engineering. PHYSICAL REVIEW LETTERS 2021; 127:083602. [PMID: 34477431 DOI: 10.1103/physrevlett.127.083602] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 07/13/2021] [Accepted: 07/26/2021] [Indexed: 06/13/2023]
Abstract
As a genuine many-body entanglement, spin squeezing (SS) can be used to realize the highly precise measurement beyond the limit constrained by classical physics. Its generation has attracted much attention recently. It was reported that N two-level systems (TLSs) located near a one-dimensional waveguide can generate SS by using the mediation effect of the waveguide. However, a coherent driving on each TLS is used to stabilize the SS, which raises a high requirement for experiments. We here propose a scheme to generate stable SS resorting to neither the spin-spin coupling nor the coherent driving on the TLSs. Incorporating the mediation role of the common waveguide and the technique of squeezed-reservoir engineering, our scheme exhibits the advantages over previous ones in the scaling relation of the SS parameter with the number of the TLSs. The long-range correlation feature of the generated SS along the waveguide in our scheme may endow it with certain superiority in quantum sensing, e.g., improving the sensing efficiency of spatially unidentified weak magnetic fields.
Collapse
Affiliation(s)
- Si-Yuan Bai
- Lanzhou Center for Theoretical Physics, Key Laboratory of Theoretical Physics of Gansu Province, Lanzhou University, Lanzhou 730000, China
| | - Jun-Hong An
- Lanzhou Center for Theoretical Physics, Key Laboratory of Theoretical Physics of Gansu Province, Lanzhou University, Lanzhou 730000, China
| |
Collapse
|
20
|
Gertler JM, Baker B, Li J, Shirol S, Koch J, Wang C. Protecting a bosonic qubit with autonomous quantum error correction. Nature 2021; 590:243-248. [PMID: 33568826 DOI: 10.1038/s41586-021-03257-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Accepted: 11/18/2020] [Indexed: 01/31/2023]
Abstract
To build a universal quantum computer from fragile physical qubits, effective implementation of quantum error correction (QEC)1 is an essential requirement and a central challenge. Existing demonstrations of QEC are based on an active schedule of error-syndrome measurements and adaptive recovery operations2,3,4,5,6,7 that are hardware intensive and prone to introducing and propagating errors. In principle, QEC can be realized autonomously and continuously by tailoring dissipation within the quantum system1,8,9,10,11,12,13,14, but so far it has remained challenging to achieve the specific form of dissipation required to counter the most prominent errors in a physical platform. Here we encode a logical qubit in Schrödinger cat-like multiphoton states15 of a superconducting cavity, and demonstrate a corrective dissipation process that stabilizes an error-syndrome operator: the photon number parity. Implemented with continuous-wave control fields only, this passive protocol protects the quantum information by autonomously correcting single-photon-loss errors and boosts the coherence time of the bosonic qubit by over a factor of two. Notably, QEC is realized in a modest hardware setup with neither high-fidelity readout nor fast digital feedback, in contrast to the technological sophistication required for prior QEC demonstrations. Compatible with additional phase-stabilization and fault-tolerant techniques16,17,18, our experiment suggests quantum dissipation engineering as a resource-efficient alternative or supplement to active QEC in future quantum computing architectures.
Collapse
Affiliation(s)
- Jeffrey M Gertler
- Department of Physics, University of Massachusetts Amherst, Amherst, MA, USA
| | - Brian Baker
- Department of Physics and Astronomy, Northwestern University, Evanston, IL, USA
| | - Juliang Li
- Department of Physics, University of Massachusetts Amherst, Amherst, MA, USA
| | - Shruti Shirol
- Department of Physics, University of Massachusetts Amherst, Amherst, MA, USA
| | - Jens Koch
- Department of Physics and Astronomy, Northwestern University, Evanston, IL, USA
| | - Chen Wang
- Department of Physics, University of Massachusetts Amherst, Amherst, MA, USA.
| |
Collapse
|
21
|
Thomas RA, Parniak M, Østfeldt C, Møller CB, Bærentsen C, Tsaturyan Y, Schliesser A, Appel J, Zeuthen E, Polzik ES. Entanglement between distant macroscopic mechanical and spin systems. NATURE PHYSICS 2021; 17:228-233. [PMID: 0 DOI: 10.1038/s41567-020-1031-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 08/06/2020] [Indexed: 05/24/2023]
|
22
|
Dutta S, Cooper NR. Long-Range Coherence and Multiple Steady States in a Lossy Qubit Array. PHYSICAL REVIEW LETTERS 2020; 125:240404. [PMID: 33412034 DOI: 10.1103/physrevlett.125.240404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 11/11/2020] [Indexed: 06/12/2023]
Abstract
We show that a simple experimental setting of a locally pumped and lossy array of two-level quantum systems can stabilize states with strong long-range coherence. Indeed, by explicit analytic construction, we show there is an extensive set of steady-state density operators, from minimally to maximally entangled, despite this being an interacting open many-body problem. Such nonequilibrium steady states arise from a hidden symmetry that stabilizes Bell pairs over arbitrarily long distances, with unique experimental signatures. We demonstrate a protocol by which one can selectively prepare these states using dissipation. Our findings are accessible in present-day experiments.
Collapse
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
| |
Collapse
|
23
|
Karg TM, Gouraud B, Ngai CT, Schmid GL, Hammerer K, Treutlein P. Light-mediated strong coupling between a mechanical oscillator and atomic spins 1 meter apart. Science 2020; 369:174-179. [DOI: 10.1126/science.abb0328] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 04/28/2020] [Indexed: 11/02/2022]
Abstract
Engineering strong interactions between quantum systems is essential for many phenomena of quantum physics and technology. Typically, strong coupling relies on short-range forces or on placing the systems in high-quality electromagnetic resonators, which restricts the range of the coupling to small distances. We used a free-space laser beam to strongly couple a collective atomic spin and a micromechanical membrane over a distance of 1 meter in a room-temperature environment. The coupling is highly tunable and allows the observation of normal-mode splitting, coherent energy exchange oscillations, two-mode thermal noise squeezing, and dissipative coupling. Our approach to engineering coherent long-distance interactions with light makes it possible to couple very different systems in a modular way, opening up a range of opportunities for quantum control and coherent feedback networks.
Collapse
Affiliation(s)
- Thomas M. Karg
- Department of Physics and Swiss Nanoscience Institute, University of Basel, 4056 Basel, Switzerland
| | - Baptiste Gouraud
- Department of Physics and Swiss Nanoscience Institute, University of Basel, 4056 Basel, Switzerland
| | - Chun Tat Ngai
- Department of Physics and Swiss Nanoscience Institute, University of Basel, 4056 Basel, Switzerland
| | - Gian-Luca Schmid
- Department of Physics and Swiss Nanoscience Institute, University of Basel, 4056 Basel, Switzerland
| | - Klemens Hammerer
- Institute for Theoretical Physics and Institute for Gravitational Physics (Albert Einstein Institute), Leibniz Universität Hannover, 30167 Hannover, Germany
| | - Philipp Treutlein
- Department of Physics and Swiss Nanoscience Institute, University of Basel, 4056 Basel, Switzerland
| |
Collapse
|
24
|
Wang S, Ma XS, Cheng MT. Multipartite Entanglement Generation in a Structured Environment. ENTROPY 2020; 22:e22020191. [PMID: 33285966 PMCID: PMC7516616 DOI: 10.3390/e22020191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 02/01/2020] [Accepted: 02/05/2020] [Indexed: 12/02/2022]
Abstract
In this paper, we investigate the entanglement generation of n-qubit states in a model consisting of n independent qubits, each coupled to a harmonic oscillator which is in turn coupled to a bath of N additional harmonic oscillators with nearest-neighbor coupling. With analysis, we can find that the steady multipartite entanglement with different values can be generated after a long-time evolution for different sizes of the quantum system. Under weak coupling between the system and the harmonic oscillator, multipartite entanglement can monotonically increase from zero to a stable value. Under strong coupling, multipartite entanglement generation shows a speed-up increase accompanied by some oscillations as non-Markovian behavior. Our results imply that the strong coupling between the harmonic oscillator and the N additional harmonic oscillators, and the large size of the additional oscillators will enhance non-Markovian dynamics and make it take a very long time for the entanglement to reach a stable value. Meanwhile, the couplings between the additional harmonic oscillators and the decay rate of additional harmonic oscillators have almost no effect on the multipartite entanglement generation. Finally, the entanglement generation of the additional harmonic oscillators is also discussed.
Collapse
|
25
|
Cao W, Lu X, Meng X, Sun J, Shen H, Xiao Y. Reservoir-Mediated Quantum Correlations in Non-Hermitian Optical System. PHYSICAL REVIEW LETTERS 2020; 124:030401. [PMID: 32031853 DOI: 10.1103/physrevlett.124.030401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Indexed: 06/10/2023]
Abstract
Recent advances in non-Hermitian physical systems have led to numerous novel optical phenomena and applications. Such systems typically involve gain and loss associated with dissipative coupling to the environment, hence interesting quantum phenomena are often washed out, rendering most realizations classical. Here, in contrast, we propose to employ dissipative coupling to enable quantum correlations. In particular, two distant optical channels are judiciously designed to couple to and exchange information with a common reservoir environment, under an anti-parity-time-symmetric setting of hot but coherent atoms. We realize a non-Hermitian nonlinear phase sensitive parametric process, where atomic motion leads to quantum correlations between two distant light beams in the symmetry-unbroken phase. This Letter starts a new route to exploring the non-Hermitian quantum phenomena by bridging the fields of atomic physics, non-Hermitian optics, quantum information, and reservoir engineering. Potential applications include novel quantum light sources, quantum information processing and sensing, and generalization to correlated many-body systems.
Collapse
Affiliation(s)
- Wanxia Cao
- Department of Physics, State Key Laboratory of Surface Physics and Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Fudan University, Shanghai 200433, China
| | - Xingda Lu
- Department of Physics, State Key Laboratory of Surface Physics and Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Fudan University, Shanghai 200433, China
| | - Xin Meng
- Department of Physics, State Key Laboratory of Surface Physics and Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Fudan University, Shanghai 200433, China
| | - Jian Sun
- Department of Physics, State Key Laboratory of Surface Physics and Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Fudan University, Shanghai 200433, China
| | - Heng Shen
- Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Yanhong Xiao
- Department of Physics, State Key Laboratory of Surface Physics and Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Fudan University, Shanghai 200433, China
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan, Shanxi 030006, China
| |
Collapse
|
26
|
Wang W, Hu X, Xu J. Coherent population trapping based atomic reservoir for almost perfect higher-order squeezing. OPTICS EXPRESS 2019; 27:30530-30551. [PMID: 31684299 DOI: 10.1364/oe.27.030530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 09/20/2019] [Indexed: 06/10/2023]
Abstract
Due to either coherent or dissipative interactions with the coherent population trapping (CPT)-based atoms, the evolutions of the Bogoliubov modes towards the vacuum states have been shown to lead to second-order squeezing of the involved optical fields. Here we push the CPT-based dissipative interactions towards higher-order squeezing, which is not simply determined by second-order squeezing but instead by different criteria involving higher-order moments. It is shown that the CPT-based atomic reservoir supports the dissipative evolution of the Bogoliubov modes almost completely to the vacuum states and then yields almost perfect fourth-order squeezing (90%∼100%). The present mechanism is robust against spontaneous emission since the atoms stay largely in the ground states. As a by-product, a comparison is given with two-level atoms, in which the excitation of a large fraction reduces the degree of higher-order squeezing.
Collapse
|
27
|
Zhao X. Macroscopic entanglement in optomechanical system induced by non-Markovian environment. OPTICS EXPRESS 2019; 27:29082-29097. [PMID: 31684649 DOI: 10.1364/oe.27.029082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 09/06/2019] [Indexed: 06/10/2023]
Abstract
In this paper, the non-Markovian dynamics of an optomechanical system is analyzed by using the non-Markovian quantum state diffusion (NMQSD) method. An exact solution is obtained for the system composed of a Fabry-Pérot (F-P) cavity with two movable mirrors without the linearization of the Hamiltonian. Based on the solution, we find that the memory effect of the non-Markovian environment can be used to generate macroscopic entanglement between two mirrors. In order to achieve the maximum entanglement generation, the non-Markovian properties of the environment have to be chosen carefully depending on the properties of the system. Then, we also show that the coherence (superposition) in the initial state may produce entanglement in the evolution. At last, we show the entanglement sudden death and revival significantly depend on the strength of the memory effect, and the entanglement revival can be only observed in non-Markovian case. Our treatment, as an example, paves a way to exactly solve a large category of optomechanical systems without the linearization of the Hamiltonian.
Collapse
|
28
|
Reid MD, He QY. Quantifying the Mesoscopic Nature of Einstein-Podolsky-Rosen Nonlocality. PHYSICAL REVIEW LETTERS 2019; 123:120402. [PMID: 31633988 DOI: 10.1103/physrevlett.123.120402] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 05/21/2019] [Indexed: 06/10/2023]
Abstract
Evidence for Bell's nonlocality is so far mainly restricted to microscopic systems, where the elements of reality that are negated predetermine results of measurements to within one spin unit. Any observed nonlocal effect (or lack of classical predetermination) is then limited to no more than the difference of a single photon or electron being detected or not (at a given detector). In this paper, we analyze experiments that report the Einstein-Podolsky-Rosen (EPR) steering form of nonlocality for mesoscopic photonic or Bose-Einstein condensate systems. Using an EPR steering parameter, we show how the EPR nonlocalities involved can be quantified for four-mode states, to give evidence of EPR-nonlocal effects corresponding to a two-mode number difference of 10^{5} photons, or of several tens of atoms (at a given site). Applying to experiments, we also show how the variance criterion of Duan, Giedke, Cirac and Zoller for EPR entanglement can be used to determine a lower bound on the number of particles in a pure two-mode EPR-entangled or steerable state.
Collapse
Affiliation(s)
- M D Reid
- Centre for Quantum and Optical Science, Swinburne University of Technology, Melbourne, Victoria 3122, Australia
- Institute of Theoretical Atomic, Molecular and Optical Physics (ITAMP), Harvard University, Cambridge, Massachusetts 02138, USA
| | - Q Y He
- State Key Laboratory of Mesoscopic Physics, School of Physics, Peking University, Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China
| |
Collapse
|
29
|
Yan XB, Deng ZJ, Tian XD, Wu JH. Entanglement optimization of filtered output fields in cavity optomechanics. OPTICS EXPRESS 2019; 27:24393-24402. [PMID: 31510328 DOI: 10.1364/oe.27.024393] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 07/28/2019] [Indexed: 06/10/2023]
Abstract
Output entanglement is a key element in quantum information processing. Here, we show how to obtain optimal entanglement between two filtered output fields in a three-mode optomechanical system. First, we obtain the key analytical expression of optimal time delay between the two filtered output fields, from which we can obtain the optimal coupling for output entanglement without time delay. In this case, our linearized analysis predicts that the entanglement saturates to an optimal value as the optomechanical coupling is increased. Furthermore, we obtain the optimal output entanglement with time delay. These results should be very helpful in conceiving new optomechanical schemes of quantum information processing with their efficiency depending critically on the degree of output entanglement.
Collapse
|
30
|
Gu WJ, Yi Z, Sun LH, Yan Y. Generation of mechanical squeezing and entanglement via mechanical modulations. OPTICS EXPRESS 2018; 26:30773-30785. [PMID: 30469969 DOI: 10.1364/oe.26.030773] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 10/29/2018] [Indexed: 06/09/2023]
Abstract
We discuss the generation of strong stationary mechanical squeezing and entanglement in the modulated two-and three-mode optomechanics. Following the reservoir engineering scheme, the beam-splitter and parametric optomechanical interactions can be simultaneously achieved through appropriately choosing the modulation frequency on mechanical motion, which is essential to strong squeezing and entanglement. In the two-mode modulated optomechanics, squeezing is tunable by the relative ratio of parametric and beam-splitter couplings, and also robust to thermal noise due to the simultaneously optically induced cooling process. In the three-mode modulated optomechanics, strong EPR-type entanglement is also attainable, which can surpass the 3dB limit of nondegenerate parametric interaction. However, the ideal entanglement is impossible since only one of mechanical Bogoliubov modes is cooled by the cavity mode, which also makes the entanglement fragile to the mechanical noise.
Collapse
|
31
|
Huang X, Zeuthen E, Vasilyev DV, He Q, Hammerer K, Polzik ES. Unconditional Steady-State Entanglement in Macroscopic Hybrid Systems by Coherent Noise Cancellation. PHYSICAL REVIEW LETTERS 2018; 121:103602. [PMID: 30240274 DOI: 10.1103/physrevlett.121.103602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Indexed: 06/08/2023]
Abstract
The generation of entanglement between disparate physical objects is a key ingredient in the field of quantum technologies, since they can have different functionalities in a quantum network. Here we propose and analyze a generic approach to steady-state entanglement generation between two oscillators with different temperatures and decoherence properties coupled in cascade to a common unidirectional light field. The scheme is based on a combination of coherent noise cancellation and dynamical cooling techniques for two oscillators with effective masses of opposite signs, such as quasispin and motional degrees of freedom, respectively. The interference effect provided by the cascaded setup can be tuned to implement additional noise cancellation leading to improved entanglement even in the presence of a hot thermal environment. The unconditional entanglement generation is advantageous since it provides a ready-to-use quantum resource. Remarkably, by comparing to the conditional entanglement achievable in the dynamically stable regime, we find our unconditional scheme to deliver a virtually identical performance when operated optimally.
Collapse
Affiliation(s)
- Xinyao Huang
- State Key Laboratory of Mesoscopic Physics, School of Physics, Peking University, Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
- Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Emil Zeuthen
- Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Denis V Vasilyev
- Center for Quantum Physics, Faculty of Mathematics, Computer Science and Physics, University of Innsbruck, A-6020 Innsbruck, Austria
- Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, A-6020 Innsbruck, Austria
| | - Qiongyi He
- State Key Laboratory of Mesoscopic Physics, School of Physics, Peking University, Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Klemens Hammerer
- Institute for Theoretical Physics and Institute for Gravitational Physics (Albert Einstein Institute), Leibniz Universität Hannover, Callinstraße 38, 30167 Hannover, Germany
| | - Eugene S Polzik
- Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen, Denmark
| |
Collapse
|
32
|
Hou QZ, You JB, Yang WL, An JH, Chen CY, Feng M. Generation of multiqubit steady-state quantum correlation by squeezed-reservoir engineering. OPTICS EXPRESS 2018; 26:20459-20470. [PMID: 30119356 DOI: 10.1364/oe.26.020459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 07/08/2018] [Indexed: 06/08/2023]
Abstract
Stationary quantum correlation among two-level systems (TLSs) in steady state is one of unique resources for applications in quantum information processing. Here we propose a scheme to generate such quantum correlation among the TLSs inside a lossy cavity. It is found that, by applying a broadband squeezed laser acting as a squeezed-vacuum reservoir to the cavity, a stable quantum correlation of the TLSs can be generated. By adiabatically eliminating the cavity field, we derive a reduced master equation of the TLSs in the bad-cavity limit. We show that the generated quantum correlation is essentially determined by the squeezing features transferred from the squeezed-vacuum reservoir via the cavity field as a quantum bus. We study the effect of the system parameters, such as the squeezing, the detuning, the coupling strength, and the decay rate of the TLSs, on the performance of the scheme. The feasibility of our proposal is supported by the application of currently available experimental techniques.
Collapse
|
33
|
Qin W, Miranowicz A, Li PB, Lü XY, You JQ, Nori F. Exponentially Enhanced Light-Matter Interaction, Cooperativities, and Steady-State Entanglement Using Parametric Amplification. PHYSICAL REVIEW LETTERS 2018; 120:093601. [PMID: 29547303 DOI: 10.1103/physrevlett.120.093601] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Indexed: 06/08/2023]
Abstract
We propose an experimentally feasible method for enhancing the atom-field coupling as well as the ratio between this coupling and dissipation (i.e., cooperativity) in an optical cavity. It exploits optical parametric amplification to exponentially enhance the atom-cavity interaction and, hence, the cooperativity of the system, with the squeezing-induced noise being completely eliminated. Consequently, the atom-cavity system can be driven from the weak-coupling regime to the strong-coupling regime for modest squeezing parameters, and even can achieve an effective cooperativity much larger than 100. Based on this, we further demonstrate the generation of steady-state nearly maximal quantum entanglement. The resulting entanglement infidelity (which quantifies the deviation of the actual state from a maximally entangled state) is exponentially smaller than the lower bound on the infidelities obtained in other dissipative entanglement preparations without applying squeezing. In principle, we can make an arbitrarily small infidelity. Our generic method for enhancing atom-cavity interaction and cooperativities can be implemented in a wide range of physical systems, and it can provide diverse applications for quantum information processing.
Collapse
Affiliation(s)
- Wei Qin
- Quantum Physics and Quantum Information Division, Beijing Computational Science Research Center, Beijing 100193, China
- CEMS, RIKEN, Wako-shi, Saitama 351-0198, Japan
| | - Adam Miranowicz
- CEMS, RIKEN, Wako-shi, Saitama 351-0198, Japan
- Faculty of Physics, Adam Mickiewicz University, 61-614 Poznań, Poland
| | - Peng-Bo Li
- CEMS, RIKEN, Wako-shi, Saitama 351-0198, Japan
- Shaanxi Province Key Laboratory of Quantum Information and Quantum Optoelectronic Devices, Department of Applied Physics, Xi'an Jiaotong University, Xi'an 710049, China
| | - Xin-You Lü
- School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - J Q You
- Quantum Physics and Quantum Information Division, Beijing Computational Science Research Center, Beijing 100193, China
- Department of Physics, Zhejiang University, Hangzhou 310027, China
| | - Franco Nori
- CEMS, RIKEN, Wako-shi, Saitama 351-0198, Japan
- Physics Department, The University of Michigan, Ann Arbor, Michigan 48109-1040, USA
| |
Collapse
|
34
|
Kohler J, Gerber JA, Dowd E, Stamper-Kurn DM. Negative-Mass Instability of the Spin and Motion of an Atomic Gas Driven by Optical Cavity Backaction. PHYSICAL REVIEW LETTERS 2018; 120:013601. [PMID: 29350956 DOI: 10.1103/physrevlett.120.013601] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Indexed: 06/07/2023]
Abstract
We realize a spin-orbit interaction between the collective spin precession and center-of-mass motion of a trapped ultracold atomic gas, mediated by spin- and position-dependent dispersive coupling to a driven optical cavity. The collective spin, precessing near its highest-energy state in an applied magnetic field, can be approximated as a negative-mass harmonic oscillator. When the Larmor precession and mechanical motion are nearly resonant, cavity mediated coupling leads to a negative-mass instability, driving exponential growth of a correlated mode of the hybrid system. We observe this growth imprinted on modulations of the cavity field and estimate the full covariance of the resulting two-mode state by observing its transient decay during subsequent free evolution.
Collapse
Affiliation(s)
- Jonathan Kohler
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - Justin A Gerber
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - Emma Dowd
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - Dan M Stamper-Kurn
- Department of Physics, University of California, Berkeley, California 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| |
Collapse
|
35
|
Reiter F, Sørensen AS, Zoller P, Muschik CA. Dissipative quantum error correction and application to quantum sensing with trapped ions. Nat Commun 2017; 8:1822. [PMID: 29180753 PMCID: PMC5704006 DOI: 10.1038/s41467-017-01895-5] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 10/24/2017] [Indexed: 11/09/2022] Open
Abstract
Quantum-enhanced measurements hold the promise to improve high-precision sensing ranging from the definition of time standards to the determination of fundamental constants of nature. However, quantum sensors lose their sensitivity in the presence of noise. To protect them, the use of quantum error-correcting codes has been proposed. Trapped ions are an excellent technological platform for both quantum sensing and quantum error correction. Here we present a quantum error correction scheme that harnesses dissipation to stabilize a trapped-ion qubit. In our approach, always-on couplings to an engineered environment protect the qubit against spin-flips or phase-flips. Our dissipative error correction scheme operates in a continuous manner without the need to perform measurements or feedback operations. We show that the resulting enhanced coherence time translates into a significantly enhanced precision for quantum measurements. Our work constitutes a stepping stone towards the paradigm of self-correcting quantum information processing.
Collapse
Affiliation(s)
- F Reiter
- Institute for Theoretical Physics, University of Innsbruck, A-6020, Innsbruck, Austria.
- Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, A-6020, Innsbruck, Austria.
- Harvard University, Department of Physics, Cambridge, MA, 02138, USA.
| | - A S Sørensen
- Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, DK-2100, Copenhagen, Denmark
| | - P Zoller
- Institute for Theoretical Physics, University of Innsbruck, A-6020, Innsbruck, Austria
- Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, A-6020, Innsbruck, Austria
| | - C A Muschik
- Institute for Theoretical Physics, University of Innsbruck, A-6020, Innsbruck, Austria
- Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, A-6020, Innsbruck, Austria
| |
Collapse
|
36
|
Chen RX, Liao CG, Lin XM. Dissipative generation of significant amount of mechanical entanglement in a coupled optomechanical system. Sci Rep 2017; 7:14497. [PMID: 29101336 PMCID: PMC5670165 DOI: 10.1038/s41598-017-15032-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 10/19/2017] [Indexed: 11/30/2022] Open
Abstract
We propose an approach for generating steady-state mechanical entanglement in a coupled optomechanical system. By applying four-tone driving lasers with weighted amplitudes and specific frequencies, we obtain an effective Hamiltonian that couples the delocalized Bogoliubov modes of the two mechanical oscillators to the cavity modes via beam-splitter-like interactions. When the mechanical decay rate is small, the Bogoliubov modes can be effectively cooled by the dissipative dynamics of the cavity modes, generating steady-state entanglement of the mechanical modes. The mechanical entanglement obtained in the stationary regime is strongly dependent on the values of the ratio of the effective optomechanical coupling strengths. Numerical simulation with the full linearized Hamiltonian shows that significant amount of mechanical entanglement can indeed be obtained by balancing the opposing effects of varying the ratio and by carefully avoiding the system parameters that may lead to amplified oscillations of the mechanical mean values detrimental to the entanglement generation.
Collapse
Affiliation(s)
- Rong-Xin Chen
- Institute for Quantum Science and Engineering, Texas A&M University, College Station, TX, 77843, USA.
| | - Chang-Geng Liao
- Fujian Provincial Key Laboratory of Quantum Manipulation and New Energy Materials, College of Physics and Energy, Fujian Normal University, Fuzhou, 350117, China.,Fujian Provincial Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Xiamen, 361005, China.,Department of Electronic Engineering, Fujian Polytechnic of Information Technology, Fuzhou, 350003, China
| | - Xiu-Min Lin
- Fujian Provincial Key Laboratory of Quantum Manipulation and New Energy Materials, College of Physics and Energy, Fujian Normal University, Fuzhou, 350117, China. .,Fujian Provincial Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Xiamen, 361005, China.
| |
Collapse
|
37
|
Zeng Y, Xu P, He X, Liu Y, Liu M, Wang J, Papoular DJ, Shlyapnikov GV, Zhan M. Entangling Two Individual Atoms of Different Isotopes via Rydberg Blockade. PHYSICAL REVIEW LETTERS 2017; 119:160502. [PMID: 29099205 DOI: 10.1103/physrevlett.119.160502] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2017] [Indexed: 06/07/2023]
Abstract
We report on the first experimental realization of the controlled-not (cnot) quantum gate and entanglement for two individual atoms of different isotopes and demonstrate a negligible cross talk between two atom qubits. The experiment is based on a strong Rydberg blockade for ^{87}Rb and ^{85}Rb atoms confined in two single-atom optical traps separated by 3.8 μm. The raw fidelities of the cnot gate and entanglement are 0.73±0.01 and 0.59±0.03, respectively, without any corrections for atom loss or trace loss. Our work has applications for simulations of many-body systems with multispecies interactions, for quantum computing, and for quantum metrology.
Collapse
Affiliation(s)
- Yong Zeng
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences-Wuhan National Laboratory for Optoelectronics, Wuhan 430071, China
- Center for Cold Atom Physics, Chinese Academy of Sciences, Wuhan 430071, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Peng Xu
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences-Wuhan National Laboratory for Optoelectronics, Wuhan 430071, China
- Center for Cold Atom Physics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Xiaodong He
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences-Wuhan National Laboratory for Optoelectronics, Wuhan 430071, China
- Center for Cold Atom Physics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Yangyang Liu
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences-Wuhan National Laboratory for Optoelectronics, Wuhan 430071, China
- Center for Cold Atom Physics, Chinese Academy of Sciences, Wuhan 430071, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Min Liu
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences-Wuhan National Laboratory for Optoelectronics, Wuhan 430071, China
- Center for Cold Atom Physics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Jin Wang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences-Wuhan National Laboratory for Optoelectronics, Wuhan 430071, China
- Center for Cold Atom Physics, Chinese Academy of Sciences, Wuhan 430071, China
| | - D J Papoular
- LPTM, UMR8089 of CNRS and Université de Cergy-Pontoise, F-95302 Cergy-Pontoise, France
| | - G V Shlyapnikov
- LPTMS, UMR8626 of CNRS and Université Paris-Sud, F-91405 Orsay, France
- SPEC, CEA & CNRS, Université Paris-Saclay, CEA Saclay, F-91191 Gif-sur-Yvette, France
- Russian Quantum Center, Novaya Street, Skolkovo, Moscow Region R-143025, Russia
- Van der Waals-Zeeman Institute, Institute of Physics, University of Amsterdam, The Netherlands
| | - Mingsheng Zhan
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences-Wuhan National Laboratory for Optoelectronics, Wuhan 430071, China
- Center for Cold Atom Physics, Chinese Academy of Sciences, Wuhan 430071, China
| |
Collapse
|
38
|
Establishing and storing of deterministic quantum entanglement among three distant atomic ensembles. Nat Commun 2017; 8:718. [PMID: 28959032 PMCID: PMC5620099 DOI: 10.1038/s41467-017-00809-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 07/28/2017] [Indexed: 11/08/2022] Open
Abstract
It is crucial for the physical realization of quantum information networks to first establish entanglement among multiple space-separated quantum memories and then, at a user-controlled moment, to transfer the stored entanglement to quantum channels for distribution and conveyance of information. Here we present an experimental demonstration on generation, storage, and transfer of deterministic quantum entanglement among three spatially separated atomic ensembles. The off-line prepared multipartite entanglement of optical modes is mapped into three distant atomic ensembles to establish entanglement of atomic spin waves via electromagnetically induced transparency light-matter interaction. Then the stored atomic entanglement is transferred into a tripartite quadrature entangled state of light, which is space-separated and can be dynamically allocated to three quantum channels for conveying quantum information. The existence of entanglement among three released optical modes verifies that the system has the capacity to preserve multipartite entanglement. The presented protocol can be directly extended to larger quantum networks with more nodes.Continuous-variable encoding is a promising approach for quantum information and communication networks. Here, the authors show how to map entanglement from three spatial optical modes to three separated atomic samples via electromagnetically induced transparency, releasing it later on demand.
Collapse
|
39
|
Song W, Yang W, An J, Feng M. Dissipation-assisted spin squeezing of nitrogen-vacancy centers coupled to a rectangular hollow metallic waveguide. OPTICS EXPRESS 2017; 25:19226-19235. [PMID: 29041116 DOI: 10.1364/oe.25.019226] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 06/10/2017] [Indexed: 06/07/2023]
Abstract
Spin squeezing has received much attention due to the interesting physics and important applications such as quantum metrology and quantum information processing. We here present a scheme to engineer stable spin squeezing in an array of nitrogen vacancy centers (NVCs) coupled to a rectangular hollow metallic waveguide. The remarkable feature of the waveguide as the common environment media is that one can switch on/off either the waveguide induced dipole-dipole interactions or correlated spontaneous emissions among the NVCs by designing their spatial separation. It permits us to achieve a dissipative Dicke model after the dipole-dipole interactions vanish due to destructive interference. With the external driving lasers on each NVC, a second-order phase transition is triggered, separating the steady state into two phases with and without collective spin squeezing. Supplying a physical realization of the dissipative Dicke model, our study gives a bridge between the generation of the stable spin squeezing and the phase transition physics.
Collapse
|
40
|
Gong Z, Higashikawa S, Ueda M. Zeno Hall Effect. PHYSICAL REVIEW LETTERS 2017; 118:200401. [PMID: 28581785 DOI: 10.1103/physrevlett.118.200401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Indexed: 06/07/2023]
Abstract
We show that the quantum Zeno effect gives rise to the Hall effect by tailoring the Hilbert space of a two-dimensional lattice system into a single Bloch band with a nontrivial Berry curvature. Consequently, a wave packet undergoes transverse motion in response to a potential gradient-a phenomenon we call the Zeno Hall effect to highlight its quantum Zeno origin. The Zeno Hall effect leads to retroreflection at the edge of the system due to an interplay between the band flatness and the nontrivial Berry curvature. We propose an experimental implementation of this effect with ultracold atoms in an optical lattice.
Collapse
Affiliation(s)
- Zongping Gong
- Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Sho Higashikawa
- Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Masahito Ueda
- Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
| |
Collapse
|
41
|
Kohler J, Spethmann N, Schreppler S, Stamper-Kurn DM. Cavity-Assisted Measurement and Coherent Control of Collective Atomic Spin Oscillators. PHYSICAL REVIEW LETTERS 2017; 118:063604. [PMID: 28234539 DOI: 10.1103/physrevlett.118.063604] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Indexed: 06/06/2023]
Abstract
We demonstrate continuous measurement and coherent control of the collective spin of an atomic ensemble undergoing Larmor precession in a high-finesse optical cavity. The coupling of the precessing spin to the cavity field yields phenomena similar to those observed in cavity optomechanics, including cavity amplification, damping, and optical spring shifts. These effects arise from autonomous optical feedback onto the atomic spin dynamics, conditioned by the cavity spectrum. We use this feedback to stabilize the spin in either its high- or low-energy state, where, in equilibrium with measurement backaction heating, it achieves a steady-state temperature, indicated by an asymmetry between the Stokes and the anti-Stokes scattering rates. For sufficiently large Larmor frequency, such feedback stabilizes the spin ensemble in a nearly pure quantum state, in spite of continuous measurement by the cavity field.
Collapse
Affiliation(s)
- Jonathan Kohler
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - Nicolas Spethmann
- Department of Physics, University of California, Berkeley, California 94720, USA
- Department of Physics and Research Center OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | - Sydney Schreppler
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - Dan M Stamper-Kurn
- Department of Physics, University of California, Berkeley, California 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| |
Collapse
|
42
|
Jin Z, Su SL, Zhu AD, Wang HF, Zhang S. Dissipative preparation of distributed steady entanglement: an approach of unilateral qubit driving. OPTICS EXPRESS 2017; 25:88-101. [PMID: 28085813 DOI: 10.1364/oe.25.000088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We propose a nonlocal scheme for preparing a distributed steady-state entanglement of two atoms trapped in separate optical cavities coupled through an optical fiber based on the combined effect of the unitary dynamics and dissipative process. In this scheme, only the qubit of one node is driven by an external classical field, while the other one does not need to be manipulated by an external field. This is meaningful for long distance quantum information processing tasks, and the experimental implementation is greatly simplified due to the unilateral manipulation on one node and the process of entanglement distribution can be avoided. This guarantees the absolute security of long distance quantum information processing tasks and makes the scheme more robust than that based on the unitary dynamics. We introduce the purity to characterize the mixture degree of the target steady-state. The steady entanglement can be obtained independent of the initial state. Furthermore, based on the dissipative entanglement preparation scheme, we construct a quantum teleportation setup with multiple nodes as a practical application, and the numerical simulation demonstrates the scheme can be realized effectively under the current experimental conditions..
Collapse
|
43
|
Nielsen WHP, Tsaturyan Y, Møller CB, Polzik ES, Schliesser A. Multimode optomechanical system in the quantum regime. Proc Natl Acad Sci U S A 2017; 114:62-66. [PMID: 27999182 PMCID: PMC5224392 DOI: 10.1073/pnas.1608412114] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We realize a simple and robust optomechanical system with a multitude of long-lived (Q > 107) mechanical modes in a phononic-bandgap shielded membrane resonator. An optical mode of a compact Fabry-Perot resonator detects these modes' motion with a measurement rate (96 kHz) that exceeds the mechanical decoherence rates already at moderate cryogenic temperatures (10 K). Reaching this quantum regime entails, inter alia, quantum measurement backaction exceeding thermal forces and thus strong optomechanical quantum correlations. In particular, we observe ponderomotive squeezing of the output light mediated by a multitude of mechanical resonator modes, with quantum noise suppression up to -2.4 dB (-3.6 dB if corrected for detection losses) and bandwidths ≲90 kHz. The multimode nature of the membrane and Fabry-Perot resonators will allow multimode entanglement involving electromagnetic, mechanical, and spin degrees of freedom.
Collapse
Affiliation(s)
| | - Yeghishe Tsaturyan
- Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | | | - Eugene S Polzik
- Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Albert Schliesser
- Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| |
Collapse
|
44
|
Overbeck VR, Maghrebi MF, Gorshkov AV, Weimer H. Multicritical behavior in dissipative Ising models. PHYSICAL REVIEW. A 2017; 95:10.1103/PhysRevA.95.042133. [PMID: 31093585 PMCID: PMC6513333 DOI: 10.1103/physreva.95.042133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
We analyze theoretically the many-body dynamics of a dissipative Ising model in a transverse field using a variational approach. We find that the steady-state phase diagram is substantially modified compared to its equilibrium counterpart, including the appearance of a multicritical point belonging to a different universality class. Building on our variational analysis, we establish a field-theoretical treatment corresponding to a dissipative variant of a Ginzburg-Landau theory, which allows us to compute the upper critical dimension of the system. Finally, we present a possible experimental realization of the dissipative Ising model using ultracold Rydberg gases.
Collapse
Affiliation(s)
- Vincent R. Overbeck
- Institut für Theoretische Physik, Leibniz Universität Hannover, Appelstraße 2, 30167 Hannover, Germany
| | - Mohammad F. Maghrebi
- Joint Quantum Institute and Joint Center for Quantum Information and Computer Science, NIST/University of Maryland, College Park, Maryland 20742, USA
| | - Alexey V. Gorshkov
- Joint Quantum Institute and Joint Center for Quantum Information and Computer Science, NIST/University of Maryland, College Park, Maryland 20742, USA
| | - Hendrik Weimer
- Institut für Theoretische Physik, Leibniz Universität Hannover, Appelstraße 2, 30167 Hannover, Germany
| |
Collapse
|
45
|
Li L, Hu X, Rao S, Xu J. Noise squeezing of fields that bichromatically excite atoms in a cavity. OPTICS EXPRESS 2016; 24:26536-26557. [PMID: 27857387 DOI: 10.1364/oe.24.026536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
It is well known that bichromatic excitation on one common transition can tune the emission or absorption spectra of atoms due to the modulation frequency dependent non-linearities. However little attention has been focused on the quantum dynamics of fields under bichromatic excitation. Here we present dissipative effects on noise correlations of fields in bichromatic interactions with atoms in cavities. We first consider an ensemble of two-level atoms that interacts with the two cavity fields of different frequencies and considerable amplitudes. By transferring the atom-field nonlinearities to the dressed atoms we separate out the dissipative interactions of Bogoliubov modes with the dressed atoms. The Bogoliubov mode dissipation establishes stable two-photon processes of two involved fields and therefore leads to two-mode squeezing. As a generalization, we then consider an ensemble of three-level Λ atoms for cascade bichromatic interactions. We extract the Bogoliubov-like four-mode interactions, which establish a quadrilateral of the two-photon processes of four involved fields and thus result in four-mode squeezing.
Collapse
|
46
|
Vool U, Shankar S, Mundhada SO, Ofek N, Narla A, Sliwa K, Zalys-Geller E, Liu Y, Frunzio L, Schoelkopf RJ, Girvin SM, Devoret MH. Continuous Quantum Nondemolition Measurement of the Transverse Component of a Qubit. PHYSICAL REVIEW LETTERS 2016; 117:133601. [PMID: 27715126 DOI: 10.1103/physrevlett.117.133601] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Indexed: 06/06/2023]
Abstract
Quantum jumps of a qubit are usually observed between its energy eigenstates, also known as its longitudinal pseudospin component. Is it possible, instead, to observe quantum jumps between the transverse superpositions of these eigenstates? We answer positively by presenting the first continuous quantum nondemolition measurement of the transverse component of an individual qubit. In a circuit QED system irradiated by two pump tones, we engineer an effective Hamiltonian whose eigenstates are the transverse qubit states, and a dispersive measurement of the corresponding operator. Such transverse component measurements are a useful tool in the driven-dissipative operation engineering toolbox, which is central to quantum simulation and quantum error correction.
Collapse
Affiliation(s)
- U Vool
- Department of Applied Physics and Physics, Yale University, New Haven, Connecticut 06520, USA
| | - S Shankar
- Department of Applied Physics and Physics, Yale University, New Haven, Connecticut 06520, USA
| | - S O Mundhada
- Department of Applied Physics and Physics, Yale University, New Haven, Connecticut 06520, USA
| | - N Ofek
- Department of Applied Physics and Physics, Yale University, New Haven, Connecticut 06520, USA
| | - A Narla
- Department of Applied Physics and Physics, Yale University, New Haven, Connecticut 06520, USA
| | - K Sliwa
- Department of Applied Physics and Physics, Yale University, New Haven, Connecticut 06520, USA
| | - E Zalys-Geller
- Department of Applied Physics and Physics, Yale University, New Haven, Connecticut 06520, USA
| | - Y Liu
- Department of Applied Physics and Physics, Yale University, New Haven, Connecticut 06520, USA
| | - L Frunzio
- Department of Applied Physics and Physics, Yale University, New Haven, Connecticut 06520, USA
| | - R J Schoelkopf
- Department of Applied Physics and Physics, Yale University, New Haven, Connecticut 06520, USA
| | - S M Girvin
- Department of Applied Physics and Physics, Yale University, New Haven, Connecticut 06520, USA
| | - M H Devoret
- Department of Applied Physics and Physics, Yale University, New Haven, Connecticut 06520, USA
| |
Collapse
|
47
|
Sieberer LM, Buchhold M, Diehl S. Keldysh field theory for driven open quantum systems. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2016; 79:096001. [PMID: 27482736 DOI: 10.1088/0034-4885/79/9/096001] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Recent experimental developments in diverse areas-ranging from cold atomic gases to light-driven semiconductors to microcavity arrays-move systems into the focus which are located on the interface of quantum optics, many-body physics and statistical mechanics. They share in common that coherent and driven-dissipative quantum dynamics occur on an equal footing, creating genuine non-equilibrium scenarios without immediate counterpart in equilibrium condensed matter physics. This concerns both their non-thermal stationary states and their many-body time evolution. It is a challenge to theory to identify novel instances of universal emergent macroscopic phenomena, which are tied unambiguously and in an observable way to the microscopic drive conditions. In this review, we discuss some recent results in this direction. Moreover, we provide a systematic introduction to the open system Keldysh functional integral approach, which is the proper technical tool to accomplish a merger of quantum optics and many-body physics, and leverages the power of modern quantum field theory to driven open quantum systems.
Collapse
Affiliation(s)
- L M Sieberer
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | | | | |
Collapse
|
48
|
Huang C, Hu X, Zhang Y, Li L, Rao S. Quantum-beat based dissipation for spin squeezing and light entanglement. OPTICS EXPRESS 2016; 24:19094-19111. [PMID: 27557189 DOI: 10.1364/oe.24.019094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We show an engineered dissipation for the spin squeezing and the light entanglement in a quantum beat system, in which two bright fields interact with an ensemble of three-level atoms in V configuration. The dissipation is based on the atom-field nonlinear interaction that is controlled by the atomic coherence between the excited states off two-photon resonance. Physical analysis and numerical verification are presented for the symmetrical parameters by using the dressed atomic states. It is shown that for particular parameters, the engineered dissipation induces almost perfect two-mode squeezing and entanglement both for the bright fields and for the dressed spins. The excited-state spin has squeezing of near 40% below the standard quantum limit although there remains the spontaneous emission from the involved excited states.
Collapse
|
49
|
Reiter F, Reeb D, Sørensen AS. Scalable Dissipative Preparation of Many-Body Entanglement. PHYSICAL REVIEW LETTERS 2016; 117:040501. [PMID: 27494463 DOI: 10.1103/physrevlett.117.040501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Indexed: 06/06/2023]
Abstract
We present a technique for the dissipative preparation of highly entangled multiparticle states of atoms coupled to common oscillator modes. By combining local spontaneous emission with coherent couplings, we engineer many-body dissipation that drives the system from an arbitrary initial state into a Greenberger-Horne-Zeilinger state. We demonstrate that using our technique highly entangled steady states can be prepared efficiently in a time that scales polynomially with the system size. Our protocol assumes generic couplings and will thus enable the dissipative production of multiparticle entanglement in a wide range of physical systems. As an example, we demonstrate the feasibility of our scheme in state-of-the-art trapped-ion systems.
Collapse
Affiliation(s)
- Florentin Reiter
- Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, DK-2100 Copenhagen, Denmark
| | - David Reeb
- Institute for Theoretical Physics, Leibniz Universität Hannover, Appelstrasse 2, 30167 Hannover, Germany
| | - Anders S Sørensen
- Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, DK-2100 Copenhagen, Denmark
| |
Collapse
|
50
|
Kimchi-Schwartz ME, Martin L, Flurin E, Aron C, Kulkarni M, Tureci HE, Siddiqi I. Stabilizing Entanglement via Symmetry-Selective Bath Engineering in Superconducting Qubits. PHYSICAL REVIEW LETTERS 2016; 116:240503. [PMID: 27367372 DOI: 10.1103/physrevlett.116.240503] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Indexed: 06/06/2023]
Abstract
Bath engineering, which utilizes coupling to lossy modes in a quantum system to generate nontrivial steady states, is a tantalizing alternative to gate- and measurement-based quantum science. Here, we demonstrate dissipative stabilization of entanglement between two superconducting transmon qubits in a symmetry-selective manner. We utilize the engineered symmetries of the dissipative environment to stabilize a target Bell state; we further demonstrate suppression of the Bell state of opposite symmetry due to parity selection rules. This implementation is resource efficient, achieves a steady-state fidelity F=0.70, and is scalable to multiple qubits.
Collapse
Affiliation(s)
- M E Kimchi-Schwartz
- Quantum Nanoelectronics Laboratory, Department of Physics, University of California, Berkeley, California 94720, USA
| | - L Martin
- Quantum Nanoelectronics Laboratory, Department of Physics, University of California, Berkeley, California 94720, USA
| | - E Flurin
- Quantum Nanoelectronics Laboratory, Department of Physics, University of California, Berkeley, California 94720, USA
| | - C Aron
- Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA
- Laboratoire de Physique Théorique, École Normale Supérieure, CNRS, Paris, France
- Instituut voor Theoretische Fysica, KU Leuven, Belgium
| | - M Kulkarni
- Department of Physics, New York City College of Technology, The City University of New York, Brooklyn, New York 11201, USA
| | - H E Tureci
- Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA
| | - I Siddiqi
- Quantum Nanoelectronics Laboratory, Department of Physics, University of California, Berkeley, California 94720, USA
| |
Collapse
|