1
|
Cui L, An S, Yit Loong Lee H, Liu GX, Wang H, Wang HY, Wu L, Dong Z, Wang L. Dynamic Ultrastrong Coupling in a 2 nm Gap Plasmonic Cavity at the Sub-Picosecond Scale. NANO LETTERS 2024. [PMID: 39038175 DOI: 10.1021/acs.nanolett.4c02288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/24/2024]
Abstract
Localized surface plasmon resonances (LSPRs) can enhance the electromagnetic fields on metallic nanostructures upon light illumination, providing an approach for manipulating light-matter interactions at the sub-wavelength scale. However, currently, there is no thorough investigation of the physical mechanism in the dynamic formation of the strongly coupled LSPRs on sub-5 nm plasmonic cavities at the sub-picosecond scale. In this work, through femtosecond broadband transient absorption spectroscopy, we reveal the dynamic ultrastrong coupling processes in a nanoparticle-in-trench (NPiT) structure containing 2 nm gap cavities, and demonstrate a coherent motional coupling between vibrating AuNPs and the nanogaps. We achieve a maximum Rabi splitting energy of ∼660 meV in the sub-picosecond hot-electron relaxation time scale under the resonant excitation of the nanogap cavity's LSPR, reaching the ultrastrong coupling regime. This leads to a change of global vibration modes for the 2 nm gap cavity, potentially related to the dynamical Casimir effect with nanogap resonators.
Collapse
Affiliation(s)
- Lin Cui
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, China
| | - Shu An
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore
| | - Henry Yit Loong Lee
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore
| | - Guang-Xin Liu
- Science, Mathematics, and Technology (SMT), Singapore University of Technology and Design (SUTD), 8 Somapah Road, Singapore 487372, Republic of Singapore
| | - Hai Wang
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, China
| | - Hai-Yu Wang
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, China
| | - Lin Wu
- Science, Mathematics, and Technology (SMT), Singapore University of Technology and Design (SUTD), 8 Somapah Road, Singapore 487372, Republic of Singapore
- Institute of High Performance Computing, Agency for Science, Technology, and Research (A*STAR), 1 Fusionopolis Way, Innovis #16-16, Singapore 138632, Republic of Singapore
| | - Zhaogang Dong
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117575, Republic of Singapore
| | - Lei Wang
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, China
| |
Collapse
|
2
|
Bao Z, Li Y, Wang Z, Wang J, Yang J, Xiong H, Song Y, Wu Y, Zhang H, Duan L. A cryogenic on-chip microwave pulse generator for large-scale superconducting quantum computing. Nat Commun 2024; 15:5958. [PMID: 39009574 PMCID: PMC11251047 DOI: 10.1038/s41467-024-50333-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 07/03/2024] [Indexed: 07/17/2024] Open
Abstract
For superconducting quantum processors, microwave signals are delivered to each qubit from room-temperature electronics to the cryogenic environment through coaxial cables. Limited by the heat load of cabling and the massive cost of electronics, such an architecture is not viable for millions of qubits required for fault-tolerant quantum computing. Monolithic integration of the control electronics and the qubits provides a promising solution, which, however, requires a coherent cryogenic microwave pulse generator that is compatible with superconducting quantum circuits. Here, we report such a signal source driven by digital-like signals, generating pulsed microwave emission with well-controlled phase, intensity, and frequency directly at millikelvin temperatures. We showcase high-fidelity readout of superconducting qubits with the microwave pulse generator. The device demonstrated here has a small footprint, negligible heat load, great flexibility to operate, and is fully compatible with today's superconducting quantum circuits, thus providing an enabling technology for large-scale superconducting quantum computers.
Collapse
Affiliation(s)
- Zenghui Bao
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, PR China
| | - Yan Li
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, PR China
| | - Zhiling Wang
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, PR China
| | - Jiahui Wang
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, PR China
| | - Jize Yang
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, PR China
| | - Haonan Xiong
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, PR China
| | - Yipu Song
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, PR China
- Hefei National Laboratory, Hefei, PR China
| | - Yukai Wu
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, PR China
- Hefei National Laboratory, Hefei, PR China
| | - Hongyi Zhang
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, PR China.
- Hefei National Laboratory, Hefei, PR China.
| | - Luming Duan
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, PR China.
- Hefei National Laboratory, Hefei, PR China.
| |
Collapse
|
3
|
Hu W, Zhang Z, Xiong W, Li M, Yan Y, Yang C, Zou Q, Lü JT, Tian H, Guo X. Direct flipping dynamics and quantized enrichment of chirality at single-molecule resolution. SCIENCE ADVANCES 2024; 10:eado1125. [PMID: 38996014 PMCID: PMC11244442 DOI: 10.1126/sciadv.ado1125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Accepted: 06/06/2024] [Indexed: 07/14/2024]
Abstract
Chirality is an important aspect of nature, and numerous macroscopic methods have been developed to understand and control chirality. For the chiral tertiary amines, their flexible flipping process makes it possible to achieve high chiral controllability without bond formation and breaking. Here, we present a type of stable chiral single-molecule devices formed by tertiary amines, using graphene-molecule-graphene single-molecule junctions. These single-molecule devices allow real-time, in situ, and long-time measurements of the flipping process of an individual chiral nitrogen center with high temporal resolution. Temperature- and bias voltage-dependent experiments, along with theoretical investigations, revealed diverse chiral intermediates, indicating the regulation of the flipping dynamics by energy-related factors. Angle-dependent measurements further demonstrated efficient enrichment of chiral states using linearly polarized light by a symmetry-related factor. This approach offers a reliable means for understanding the chirality's origin, elucidating microscopic chirality regulation mechanisms, and aiding in the design of effective drugs.
Collapse
Affiliation(s)
- Weilin Hu
- Beijing National Laboratory for Molecular Sciences, National Biomedical Imaging Center, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, Beijing 100871, P. R. China
| | - Zhiyun Zhang
- Key Laboratory for Advanced Materials and Feringa Nobel Prize Scientist Joint Research Center, Frontiers Science Center for Materiobiology and Dynamic Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, P. R. China
| | - Wan Xiong
- School of Physics, Institute for Quantum Science and Engineering and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074, P. R. China
| | - Mingyao Li
- Beijing National Laboratory for Molecular Sciences, National Biomedical Imaging Center, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, Beijing 100871, P. R. China
| | - Yong Yan
- Beijing National Laboratory for Molecular Sciences, National Biomedical Imaging Center, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, Beijing 100871, P. R. China
- Center for Molecular Systems and Organic Devices, Key Laboratory for Organic Electronics and Information Displays and Institute of Advanced Materials, Nanjing University of Posts and Telecommunications, Nanjing 210023, P. R. China
| | - Caiyao Yang
- Beijing National Laboratory for Molecular Sciences, National Biomedical Imaging Center, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, Beijing 100871, P. R. China
| | - Qi Zou
- Key Laboratory for Advanced Materials and Feringa Nobel Prize Scientist Joint Research Center, Frontiers Science Center for Materiobiology and Dynamic Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, P. R. China
| | - Jing-Tao Lü
- School of Physics, Institute for Quantum Science and Engineering and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074, P. R. China
| | - He Tian
- Key Laboratory for Advanced Materials and Feringa Nobel Prize Scientist Joint Research Center, Frontiers Science Center for Materiobiology and Dynamic Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, P. R. China
| | - Xuefeng Guo
- Beijing National Laboratory for Molecular Sciences, National Biomedical Imaging Center, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, Beijing 100871, P. R. China
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, P. R. China
| |
Collapse
|
4
|
Bar-Hillel L, Dikopoltsev A, Kam A, Sharabi Y, Segal O, Lustig E, Segev M. Time Refraction and Time Reflection above Critical Angle for Total Internal Reflection. PHYSICAL REVIEW LETTERS 2024; 132:263802. [PMID: 38996327 DOI: 10.1103/physrevlett.132.263802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 05/03/2024] [Indexed: 07/14/2024]
Abstract
We study the time reflection and time refraction of waves caused by a spatial interface with a medium undergoing a sudden temporal change in permittivity. We show that monochromatic waves are transformed into a pulse by the permittivity change, and that time reflection is enhanced at the vicinity of the critical angle for total internal reflection. In this regime, we find that the evanescent field is transformed into a propagating pulse by the sudden change in permittivity. These effects display enhancement of the time reflection and high sensitivity near the critical angle, paving the way to experiments on time reflection and photonic time crystals at optical frequencies.
Collapse
Affiliation(s)
| | | | | | | | - Ohad Segal
- Department of Electrical and Computer Engineering, Technion, Haifa 32000, Israel
| | | | | |
Collapse
|
5
|
Braidotti MC, Vinante A, Cromb M, Sandakumar A, Faccio D, Ulbricht H. Amplification of electromagnetic fields by a rotating body. Nat Commun 2024; 15:5453. [PMID: 38937453 PMCID: PMC11211504 DOI: 10.1038/s41467-024-49689-w] [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: 12/12/2023] [Accepted: 06/11/2024] [Indexed: 06/29/2024] Open
Abstract
In 1971, Zel'dovich predicted the amplification of electromagnetic (EM) waves scattered by a rotating metallic cylinder, gaining mechanical rotational energy from the body. This phenomenon was believed to be unobservable with electromagnetic fields due to technological difficulties in meeting the condition of amplification that is, the cylinder must rotate faster than the frequency of the incoming radiation. Here, we measure the amplification of an electromagnetic field, generated by a toroid LC-circuit, scattered by an aluminium cylinder spinning in the toroid gap. We show that when the Zel'dovich condition is met, the resistance induced by the cylinder becomes negative implying amplification of the incoming EM fields. These results reveal the connection between the concept of induction generators and the physics of this fundamental physics effect and open new prospects towards testing the Zel'dovich mechanism in the quantum regime, as well as related quantum friction effects.
Collapse
Affiliation(s)
- M C Braidotti
- School of Physics and Astronomy, University of Glasgow, G12 8QQ, Glasgow, UK
| | - A Vinante
- Istituto di Fotonica e Nanotecnologie - CNR and Fondazione Bruno Kessler, I-38123, Povo, Trento, Italy
| | - M Cromb
- School of Physics and Astronomy, University of Southampton, SO17 1BJ, Southampton, UK
| | - A Sandakumar
- School of Physics and Astronomy, University of Southampton, SO17 1BJ, Southampton, UK
| | - D Faccio
- School of Physics and Astronomy, University of Glasgow, G12 8QQ, Glasgow, UK
- Institute of Photonics and Quantum Sciences, Heriot-Watt University, EH14 4AS, Edinburgh, UK
| | - H Ulbricht
- School of Physics and Astronomy, University of Southampton, SO17 1BJ, Southampton, UK.
| |
Collapse
|
6
|
Dantchev D. On Casimir and Helmholtz Fluctuation-Induced Forces in Micro- and Nano-Systems: Survey of Some Basic Results. ENTROPY (BASEL, SWITZERLAND) 2024; 26:499. [PMID: 38920508 PMCID: PMC11202628 DOI: 10.3390/e26060499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 05/31/2024] [Accepted: 06/05/2024] [Indexed: 06/27/2024]
Abstract
Fluctuations are omnipresent; they exist in any matter, due either to its quantum nature or to its nonzero temperature. In the current review, we briefly cover the quantum electrodynamic Casimir (QED) force as well as the critical Casimir (CC) and Helmholtz (HF) forces. In the QED case, the medium is usually a vacuum and the massless excitations are photons, while in the CC and HF cases the medium is usually a critical or correlated fluid and the fluctuations of the order parameter are the cause of the force between the macroscopic or mesoscopic bodies immersed in it. We discuss the importance of the presented results for nanotechnology, especially for devising and assembling micro- or nano-scale systems. Several important problems for nanotechnology following from the currently available experimental findings are spelled out, and possible strategies for overcoming them are sketched. Regarding the example of HF, we explicitly demonstrate that when a given integral quantity characterizing the fluid is conserved, it has an essential influence on the behavior of the corresponding fluctuation-induced force.
Collapse
Affiliation(s)
- Daniel Dantchev
- Institute of Mechanics, Bulgarian Academy of Sciences, Academic Georgy Bonchev St., Building 4, 1113 Sofia, Bulgaria;
- Max-Planck-Institut für Intelligente Systeme, Heisenbergstrasse 3, D-70569 Stuttgart, Germany
| |
Collapse
|
7
|
Svidzinsky A. Time reflection of light from a quantum perspective and vacuum entanglement. OPTICS EXPRESS 2024; 32:15623-15644. [PMID: 38859209 DOI: 10.1364/oe.520671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 04/02/2024] [Indexed: 06/12/2024]
Abstract
If a boundary between two static media is moving with a constant superluminal velocity, or there is a sudden change of the refractive index with time, this yields generation of entangled pairs of photons out of vacuum propagating in the opposite directions. Here we show that during this process, entanglement of Minkowski vacuum is transferred to the entanglement of the generated photon pairs. If initially an electromagnetic pulse is present in the medium the photon generation is stimulated into the pulse mode, and since photons are created as entangled pairs the counter-propagating photon partners produce a pulse moving in the opposite direction, which is known as time reflection. Thus, time reflection occurs due to stimulated generation of the entangled photon pairs out of entangled vacuum and no photons in the original pulse are in fact being reflected. This is different from the mechanism of light reflection from spatial inhomogeneities for which no photons are generated.
Collapse
|
8
|
Todorov Y, Dhillon S, Mangeney J. THz quantum gap: exploring potential approaches for generating and detecting non-classical states of THz light. NANOPHOTONICS 2024; 13:1681-1691. [PMID: 38681681 PMCID: PMC11052537 DOI: 10.1515/nanoph-2023-0757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 12/30/2023] [Indexed: 05/01/2024]
Abstract
Over the past few decades, THz technology has made considerable progress, evidenced by the performance of current THz sources and detectors, as well as the emergence of several THz applications. However, in the realm of quantum technologies, the THz spectral domain is still in its infancy, unlike neighboring spectral domains that have flourished in recent years. Notably, in the microwave domain, superconducting qubits currently serve as the core of quantum computers, while quantum cryptography protocols have been successfully demonstrated in the visible and telecommunications domains through satellite links. The THz domain has lagged behind in these impressive advancements. Today, the current gap in the THz domain clearly concerns quantum technologies. Nonetheless, the emergence of quantum technologies operating at THz frequencies will potentially have a significant impact. Indeed, THz radiation holds significant promise for wireless communications with ultimate security owing to its low sensitivity to atmospheric disturbances. Moreover, it has the potential to raise the operating temperature of solid-state qubits, effectively addressing existing scalability issues. In addition, THz radiation can manipulate the quantum states of molecules, which are recognized as new platforms for quantum computation and simulation with long range interactions. Finally, its ability to penetrate generally opaque materials or its resistance to Rayleigh scattering are very appealing features for quantum sensing. In this perspective, we will discuss potential approaches that offer exciting prospects for generating and detecting non-classical states of THz light, thereby opening doors to significant breakthroughs in THz quantum technologies.
Collapse
Affiliation(s)
- Yanko Todorov
- Laboratoire de Physique de l’Ecole normale supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris-Diderot, Sorbonne Paris Cité, Paris, France
| | - Sukhdeep Dhillon
- Laboratoire de Physique de l’Ecole normale supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris-Diderot, Sorbonne Paris Cité, Paris, France
| | - Juliette Mangeney
- Laboratoire de Physique de l’Ecole normale supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris-Diderot, Sorbonne Paris Cité, Paris, France
| |
Collapse
|
9
|
Del Grosso NF, Lombardo FC, Mazzitelli FD, Villar PI. Adiabatic Shortcuts Completion in Quantum Field Theory: Annihilation of Created Particles. ENTROPY (BASEL, SWITZERLAND) 2023; 25:1249. [PMID: 37761548 PMCID: PMC10529776 DOI: 10.3390/e25091249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 08/16/2023] [Accepted: 08/19/2023] [Indexed: 09/29/2023]
Abstract
Shortcuts to adiabaticity (STA) are relevant in the context of quantum systems, particularly regarding their control when they are subjected to time-dependent external conditions. In this paper, we investigate the completion of a nonadiabatic evolution into a shortcut to adiabaticity for a quantum field confined within a one-dimensional cavity containing two movable mirrors. Expanding upon our prior research, we characterize the field's state using two Moore functions that enables us to apply reverse engineering techniques in constructing the STA. Regardless of the initial evolution, we achieve a smooth extension of the Moore functions that implements the STA. This extension facilitates the computation of the mirrors' trajectories based on the aforementioned functions. Additionally, we draw attention to the existence of a comparable problem within nonrelativistic quantum mechanics.
Collapse
Affiliation(s)
- Nicolás F. Del Grosso
- Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires 1428, Argentina;
- Instituto de Física de Buenos Aires (IFIBA), CONICET—Universidad de Buenos Aires, Buenos Aires 1428, Argentina
| | - Fernando C. Lombardo
- Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires 1428, Argentina;
- Instituto de Física de Buenos Aires (IFIBA), CONICET—Universidad de Buenos Aires, Buenos Aires 1428, Argentina
| | - Francisco D. Mazzitelli
- Centro Atómico Bariloche and Instituto Balseiro, Comisión Nacional de Energía Atómica, Bariloche 8400, Argentina;
| | - Paula I. Villar
- Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires 1428, Argentina;
- Instituto de Física de Buenos Aires (IFIBA), CONICET—Universidad de Buenos Aires, Buenos Aires 1428, Argentina
| |
Collapse
|
10
|
Wang SP, Ridolfo A, Li T, Savasta S, Nori F, Nakamura Y, You JQ. Probing the symmetry breaking of a light-matter system by an ancillary qubit. Nat Commun 2023; 14:4397. [PMID: 37474535 PMCID: PMC10359332 DOI: 10.1038/s41467-023-40097-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 07/11/2023] [Indexed: 07/22/2023] Open
Abstract
Hybrid quantum systems in the ultrastrong, and even more in the deep-strong, coupling regimes can exhibit exotic physical phenomena and promise new applications in quantum technologies. In these nonperturbative regimes, a qubit-resonator system has an entangled quantum vacuum with a nonzero average photon number in the resonator, where the photons are virtual and cannot be directly detected. The vacuum field, however, is able to induce the symmetry breaking of a dispersively coupled probe qubit. We experimentally observe the parity symmetry breaking of an ancillary Xmon artificial atom induced by the field of a lumped-element superconducting resonator deep-strongly coupled with a flux qubit. This result opens a way to experimentally explore the novel quantum-vacuum effects emerging in the deep-strong coupling regime.
Collapse
Affiliation(s)
- Shuai-Peng Wang
- Quantum Physics and Quantum Information Division, Beijing Computational Science Research Center, Beijing, 100193, China
- Interdisciplinary Center of Quantum Information, State Key Laboratory of Extreme Photonics and Instrumentation, and Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University, Hangzhou, 310027, China
| | - Alessandro Ridolfo
- Dipartimento di Fisica e Astronomia, Università di Catania, 95123, Catania, Italy
| | - Tiefu Li
- School of Integrated Circuits, and Frontier Science Center for Quantum Information, Tsinghua University, Beijing, 100084, China.
- Beijing Academy of Quantum Information Sciences, Beijing, 100193, China.
| | - Salvatore Savasta
- Dipartimento di Scienze Matematiche e Informatiche, Scienze Fisiche e Scienze della Terra, Università di Messina, I-98166, Messina, Italy.
| | - Franco Nori
- Theoretical Quantum Physics Laboratory, Cluster for Pioneering Research, RIKEN, Wako, Saitama, 351-0198, Japan
- Physics Department, The University of Michigan, Ann Arbor, MI, 48109-1040, USA
- RIKEN Center for Quantum Computing (RQC), Wako, Saitama, 351-0198, Japan
| | - Y Nakamura
- RIKEN Center for Quantum Computing (RQC), Wako, Saitama, 351-0198, Japan
- Department of Applied Physics, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - J Q You
- Interdisciplinary Center of Quantum Information, State Key Laboratory of Extreme Photonics and Instrumentation, and Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University, Hangzhou, 310027, China.
| |
Collapse
|
11
|
Roques-Carmes C, Salamin Y, Sloan J, Choi S, Velez G, Koskas E, Rivera N, Kooi SE, Joannopoulos JD, Soljačić M. Biasing the quantum vacuum to control macroscopic probability distributions. Science 2023; 381:205-209. [PMID: 37440648 DOI: 10.1126/science.adh4920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 06/06/2023] [Indexed: 07/15/2023]
Abstract
Quantum field theory suggests that electromagnetic fields naturally fluctuate, and these fluctuations can be harnessed as a source of perfect randomness. Many potential applications of randomness rely on controllable probability distributions. We show that vacuum-level bias fields injected into multistable optical systems enable a controllable source of quantum randomness, and we demonstrated this concept in an optical parametric oscillator (OPO). By injecting bias pulses with less than one photon on average, we controlled the probabilities of the two possible OPO output states. The potential of our approach for sensing sub-photon-level fields was demonstrated by reconstructing the temporal shape of fields below the single-photon level. Our results provide a platform to study quantum dynamics in nonlinear driven-dissipative systems and point toward applications in probabilistic computing and weak field sensing.
Collapse
Affiliation(s)
| | - Yannick Salamin
- Research Laboratory of Electronics, MIT, Cambridge, MA, USA
- Department of Physics, MIT, Cambridge, MA, USA
| | - Jamison Sloan
- Research Laboratory of Electronics, MIT, Cambridge, MA, USA
| | - Seou Choi
- Research Laboratory of Electronics, MIT, Cambridge, MA, USA
| | - Gustavo Velez
- Research Laboratory of Electronics, MIT, Cambridge, MA, USA
| | - Ethan Koskas
- Research Laboratory of Electronics, MIT, Cambridge, MA, USA
| | - Nicholas Rivera
- Department of Physics, MIT, Cambridge, MA, USA
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Steven E Kooi
- Institute for Soldier Nanotechnologies, MIT, Cambridge, MA, USA
| | - John D Joannopoulos
- Department of Physics, MIT, Cambridge, MA, USA
- Institute for Soldier Nanotechnologies, MIT, Cambridge, MA, USA
| | - Marin Soljačić
- Research Laboratory of Electronics, MIT, Cambridge, MA, USA
- Department of Physics, MIT, Cambridge, MA, USA
| |
Collapse
|
12
|
Zheng JC, Li PB. Few-photon isolation in a one-dimensional waveguide using chiral quantum coupling. OPTICS EXPRESS 2023; 31:21881-21898. [PMID: 37381275 DOI: 10.1364/oe.493004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 05/30/2023] [Indexed: 06/30/2023]
Abstract
We investigated the transmission of single and two photons in a one-dimensional waveguide that is coupled with a Kerr micro-ring resonator and a polarized quantum emitter. In both cases, a phase shift occurs, and the non-reciprocal behavior of the system is attributed to the unbalanced coupling between the quantum emitter and the resonator. Our analytical solutions and numerical simulations demonstrate that the nonlinear resonator scattering causes the energy redistribution of the two photons through the bound state. When the system is in the two-photon resonance state, the polarization of the correlated two photons is locked to their propagation direction, leading to non-reciprocity. As a result, our configuration can act as an optical diode.
Collapse
|
13
|
de Paula MVS, Sinesio WWT, Dodonov AV. Ancilla-Assisted Generation of Photons from Vacuum via Time-Modulation of Extracavity Qubit. ENTROPY (BASEL, SWITZERLAND) 2023; 25:901. [PMID: 37372245 DOI: 10.3390/e25060901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 05/14/2023] [Accepted: 05/22/2023] [Indexed: 06/29/2023]
Abstract
We propose a scheme for the generation of photons from a vacuum via time-modulation of a quantum system indirectly coupled to the cavity field through some ancilla quantum subsystem. We consider the simplest case when the modulation is applied to an artificial two-level atom (we call 't-qubit', that can be located even outside the cavity), while the ancilla is a stationary qubit coupled via the dipole interaction both to the cavity and t-qubit. We find that tripartite entangled states with a small number of photons can be generated from the system ground state under resonant modulations, even when the t-qubit is far detuned from both the ancilla and the cavity, provided its bare and modulation frequencies are properly adjusted. We attest our approximate analytic results by numeric simulations and show that photon generation from vacuum persists in the presence of common dissipation mechanisms.
Collapse
Affiliation(s)
- Marcos V S de Paula
- Institute of Physics, University of Brasilia, Caixa Postal 04455, Brasilia 70910-900, DF, Brazil
| | - William W T Sinesio
- Institute of Physics, University of Brasilia, Caixa Postal 04455, Brasilia 70910-900, DF, Brazil
| | - Alexandre V Dodonov
- Institute of Physics, University of Brasilia, Caixa Postal 04455, Brasilia 70910-900, DF, Brazil
- International Center of Physics, Institute of Physics, University of Brasilia, Brasilia 70910-900, DF, Brazil
| |
Collapse
|
14
|
Vettoliere A, Granata C. Highly Sensitive Tunable Magnetometer Based on Superconducting Quantum Interference Device. SENSORS (BASEL, SWITZERLAND) 2023; 23:s23073558. [PMID: 37050617 PMCID: PMC10098524 DOI: 10.3390/s23073558] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/20/2023] [Accepted: 03/27/2023] [Indexed: 06/12/2023]
Abstract
In the present article, experimental results regarding fully integrated superconducting quantum interference devices (SQUID), including a circuit to tune and optimize the main sensor device characteristics, are reported. We show the possibility of modifying the critical current of a SQUID magnetometer in liquid helium by means of a suitable heating circuit. This allows us to improve the characteristics of the SQUID sensor and in particular to optimize the voltage-magnetic flux characteristic and the relative transfer factor (responsivity) and consequently to also improve the flux and magnetic field noise. It is also possible to reset the SQUID sensor in case of entrapment of magnetic flux, avoiding taking it out of the helium bath. These results are very useful in view of most SQUID applications such as those requiring large multichannel systems in which it is desirable to optimize and eventually reset the magnetic sensors in a simple and effective way.
Collapse
|
15
|
Jolin SW, Andersson G, Hernández JCR, Strandberg I, Quijandría F, Aumentado J, Borgani R, Tholén MO, Haviland DB. Multipartite Entanglement in a Microwave Frequency Comb. PHYSICAL REVIEW LETTERS 2023; 130:120601. [PMID: 37027873 DOI: 10.1103/physrevlett.130.120601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 02/23/2023] [Indexed: 06/19/2023]
Abstract
Significant progress has been made with multipartite entanglement of discrete qubits, but continuous variable systems may provide a more scalable path toward entanglement of large ensembles. We demonstrate multipartite entanglement in a microwave frequency comb generated by a Josephson parametric amplifier subject to a bichromatic pump. We find 64 correlated modes in the transmission line using a multifrequency digital signal processing platform. Full inseparability is verified in a subset of seven modes. Our method can be expanded to generate even more entangled modes in the near future.
Collapse
Affiliation(s)
- Shan W Jolin
- Department of Applied Physics, KTH Royal Institute of Technology, SE-106 91 Stockholm, Sweden
| | - Gustav Andersson
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
- Department of Microtechnology and Nanoscience MC2, Chalmers University of Technology, SE-412 96 Göteborg, Sweden
| | - J C Rivera Hernández
- Department of Applied Physics, KTH Royal Institute of Technology, SE-106 91 Stockholm, Sweden
| | - Ingrid Strandberg
- Department of Microtechnology and Nanoscience MC2, Chalmers University of Technology, SE-412 96 Göteborg, Sweden
| | - Fernando Quijandría
- Department of Microtechnology and Nanoscience MC2, Chalmers University of Technology, SE-412 96 Göteborg, Sweden
| | - José Aumentado
- National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA
| | - Riccardo Borgani
- Department of Applied Physics, KTH Royal Institute of Technology, SE-106 91 Stockholm, Sweden
- Intermodulation Products AB, SE-823 93 Segersta, Sweden
| | - Mats O Tholén
- Department of Applied Physics, KTH Royal Institute of Technology, SE-106 91 Stockholm, Sweden
- Intermodulation Products AB, SE-823 93 Segersta, Sweden
| | - David B Haviland
- Department of Applied Physics, KTH Royal Institute of Technology, SE-106 91 Stockholm, Sweden
| |
Collapse
|
16
|
Mantiñan M, Mazzitelli FD, Trombetta LG. Stochastic Particle Creation: From the Dynamical Casimir Effect to Cosmology. ENTROPY (BASEL, SWITZERLAND) 2023; 25:151. [PMID: 36673292 PMCID: PMC9857574 DOI: 10.3390/e25010151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 01/07/2023] [Accepted: 01/08/2023] [Indexed: 06/17/2023]
Abstract
We study a stochastic version of the dynamical Casimir effect, computing the particle creation inside a cavity produced by a random motion of one of its walls. We first present a calculation perturbative in the amplitude of the motion. We compare the stochastic particle creation with the deterministic counterpart. Then, we go beyond the perturbative evaluation using a stochastic version of the multiple scale analysis, that takes into account stochastic parametric resonance. We stress the relevance of the coupling between the different modes induced by the stochastic motion. In the single-mode approximation, the equations are formally analogous to those that describe the stochastic particle creation in a cosmological context, that we rederive using multiple scale analysis.
Collapse
Affiliation(s)
- Matías Mantiñan
- Department of Physics, University of Chicago, Chicago, IL 60637, USA
| | - Francisco D. Mazzitelli
- Centro Atómico Bariloche and Instituto Balseiro, Comisión Nacional de Energía Atómica, Bariloche R8402AGP, Argentina
| | - Leonardo G. Trombetta
- CEICO, Institute of Physics of the Czech Academy of Sciences, Na Slovance 1999/2, 18221 Prague, Czech Republic
| |
Collapse
|
17
|
Timashev SF. Atom As an Open Dissipative System in the Basic Environment–the Electromagnetic Component of a Physical Vacuum: Phenomenology. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2022. [DOI: 10.1134/s0036024422120287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
18
|
Wei R, Li J, Wang W, Meng S, Zhang B, Guo Q. Comparison of SNR gain between quantum illumination radar and classical radar. OPTICS EXPRESS 2022; 30:36167-36175. [PMID: 36258552 DOI: 10.1364/oe.468158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 09/09/2022] [Indexed: 06/16/2023]
Abstract
It has been proved that quantum illumination (QI) radar has the quantum advantages in error-probability exponent. However, the error-probability exponent is not a recognized figure of merit in the radar literature, nor does it correspond in a straightforward manner to any such figure of merit. Signal to noise ratio (SNR) gain is an important criterion in radar theory. While, the theoretical analysis of quantum enhancement in SNR gain of QI radar has not been reported. In this paper, we compare the physical fundamental of matched filter (MF), which can achieve the optimal SNR gain under white noise in classical radar theory, and phase conjugation (PC) receiver. Furthermore, the quantum enhancement of SNR gain in QI radar is studied. It is shown that QI radar with practical receivers can achieve about 3dB quantum advantage in SNR gain. In addition, in the case of extremely weak signal, it can potentially achieve tens of dB enhancement in SNR gain compared with the MF based classical radar.
Collapse
|
19
|
Tian Z, Wu L, Zhang L, Jing J, Du J. Probing Lorentz-invariance-violation-induced nonthermal Unruh effect in quasi-two-dimensional dipolar condensates. Int J Clin Exp Med 2022. [DOI: 10.1103/physrevd.106.l061701] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
20
|
Timashev SF. On the Physical Nature of Quantum Mechanics and Gravitation: Phenomenology. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2022. [DOI: 10.1134/s0036024422080246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
21
|
Faccio D, Wright EM. To make a mirrorless laser. Science 2022; 377:368. [PMID: 35862541 DOI: 10.1126/science.abq5012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Periodic temporal modulation of a photonic crystal can be used to produce laser light.
Collapse
Affiliation(s)
- Daniele Faccio
- School of Physics and Astronomy, University of Glasgow, Glasgow, UK
| | - Ewan M Wright
- Wyant College of Optical Sciences, University of Arizona, Tucson, AZ 85721, USA
| |
Collapse
|
22
|
Müller MM, Said RS, Jelezko F, Calarco T, Montangero S. One decade of quantum optimal control in the chopped random basis. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2022; 85:076001. [PMID: 35605567 DOI: 10.1088/1361-6633/ac723c] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 05/23/2022] [Indexed: 06/15/2023]
Abstract
The chopped random basis (CRAB) ansatz for quantum optimal control has been proven to be a versatile tool to enable quantum technology applications such as quantum computing, quantum simulation, quantum sensing, and quantum communication. Its capability to encompass experimental constraints-while maintaining an access to the usually trap-free control landscape-and to switch from open-loop to closed-loop optimization (including with remote access-or RedCRAB) is contributing to the development of quantum technology on many different physical platforms. In this review article we present the development, the theoretical basis and the toolbox for this optimization algorithm, as well as an overview of the broad range of different theoretical and experimental applications that exploit this powerful technique.
Collapse
Affiliation(s)
- Matthias M Müller
- Peter Grünberg Institute-Quantum Control (PGI-8), Forschungszentrum Jülich GmbH, D-52425 Germany
| | - Ressa S Said
- Institute for Quantum Optics & Center for Integrated Quantum Science and Technology, Universität Ulm, D-89081 Germany
| | - Fedor Jelezko
- Institute for Quantum Optics & Center for Integrated Quantum Science and Technology, Universität Ulm, D-89081 Germany
| | - Tommaso Calarco
- Peter Grünberg Institute-Quantum Control (PGI-8), Forschungszentrum Jülich GmbH, D-52425 Germany
- Institute for Theoretical Physics, University of Cologne, D-50937 Germany
| | - Simone Montangero
- Dipartimento di Fisica e Astronomia 'G. Galilei', Università degli Studi di Padova & INFN, Sezione di Padova, I-35131 Italy
- Padua Quantum Technology Center, Università degli Studi di Padova, I-35131 Italy
| |
Collapse
|
23
|
Du L, Zhang Y, Wu JH, Kockum AF, Li Y. Giant Atoms in a Synthetic Frequency Dimension. PHYSICAL REVIEW LETTERS 2022; 128:223602. [PMID: 35714262 DOI: 10.1103/physrevlett.128.223602] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 03/03/2022] [Accepted: 05/13/2022] [Indexed: 06/15/2023]
Abstract
Giant atoms that interact with real-space waveguides at multiple spatial points have attracted extensive attention due to their unique interference effects. Here we propose a feasible scheme for constructing giant atoms in a synthetic frequency dimension with, e.g., a dynamically modulated superconducting resonator and a tailored three-level artificial atom. Both analytical and numerical calculations show good agreement between our scheme and real-space two-level giant atoms. In particular, the symmetry of the model in momentum space can be broken by tuning the phase of the external field applied on the atom, enabling chiral interactions between the atom and the frequency lattice. We further demonstrate the possibility of simulating cascaded interaction and directional excitation transfer in the frequency dimension by directly extending our model to involve more such effective giant atoms.
Collapse
Affiliation(s)
- Lei Du
- Beijing Computational Science Research Center, Beijing 100193, China
| | - Yan Zhang
- Center for Quantum Sciences and School of Physics, Northeast Normal University, Changchun 130024, China
| | - Jin-Hui Wu
- Center for Quantum Sciences and School of Physics, Northeast Normal University, Changchun 130024, China
| | - Anton Frisk Kockum
- Department of Microtechnology and Nanoscience (MC2), Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | - Yong Li
- Beijing Computational Science Research Center, Beijing 100193, China
- Center for Theoretical Physics and School of Science, Hainan University, Haikou 570228, China
- Synergetic Innovation Center for Quantum Effects and Applications, Hunan Normal University, Changsha 410081, China
| |
Collapse
|
24
|
Analogue cosmological particle creation in an ultracold quantum fluid of light. Nat Commun 2022; 13:2890. [PMID: 35614054 PMCID: PMC9133100 DOI: 10.1038/s41467-022-30603-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 05/10/2022] [Indexed: 12/01/2022] Open
Abstract
The rapid expansion of the early universe resulted in the spontaneous production of cosmological particles from vacuum fluctuations, some of which are observable today in the cosmic microwave background anisotropy. The analogue of cosmological particle creation in a quantum fluid was proposed, but the quantum, spontaneous effect due to vacuum fluctuations has not yet been observed. Here we report the spontaneous creation of analogue cosmological particles in the laboratory, using a quenched 3-dimensional quantum fluid of light. We observe acoustic peaks in the density power spectrum, in close quantitative agreement with the quantum-field theoretical prediction. We find that the long-wavelength particles provide a window to early times. This work introduces the quantum fluid of light, as cold as an atomic Bose-Einstein condensate. Under certain conditions light can act as a fluid like a Bose-Einstein condensate. Here the authors discuss an analogy of cosmological particle creation using such a quantum fluid of light.
Collapse
|
25
|
Li S, Yan XX, Gao JH, Hu Y. Circuit quantum electrodynamics simulator of the two-dimensional Su-Schrieffer-Heeger model: higher-order topological phase transition induced by a continuously varying magnetic field. OPTICS EXPRESS 2022; 30:17054-17069. [PMID: 36221536 DOI: 10.1364/oe.452216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 04/24/2022] [Indexed: 06/16/2023]
Abstract
Higher-order topological insulator (HOTI) occupies an important position in topological band theory due to its exotic bulk-edge correspondence. Recently, it has been predicted that external magnetic field can induce novel topological phases in 2D HOTIs. However, up to now the theoretical description is still incomplete and the experimental realization is still lacking. Here we proposed a superconducting quantum circuit simulator of 2D Su-Schriffer-Heeger lattice, which is one of the most celebrated HOTI models, and investigate consequently the influence of the continuously varying magnetic field. By using the parametric conversion coupling method, we can establish in principle the time- and site-resolved tunable hopping constants in the proposed architecture, thus providing an ideal platform for investigating the higher-order topological phase transitions induced by continuously varying magnetic field. Our numerical calculation further shows that the higher-order topology of the lattice, which manifests itself through the existence of the zero energy corner modes, exhibit exotic and rich dependence on the imposed magnetic field and the inhomogeneous hopping strength. To probe the proposed magnetic-field-induced topological phase transition, we study the response of the lattice to the corner site pumping in the steady state limit, with results implying that the predicted topological phase boundaries can be unambiguously identified by the measurement of the corner sites and their few neighbors. Requiring only current level of technology, our scheme can be readily tested in experiment and may pave an alternative way towards the future investigation of HOTIs under various mechanisms including magnetic field, disorder, and strong correlation.
Collapse
|
26
|
Xu K, Zhang YR, Sun ZH, Li H, Song P, Xiang Z, Huang K, Li H, Shi YH, Chen CT, Song X, Zheng D, Nori F, Wang H, Fan H. Metrological Characterization of Non-Gaussian Entangled States of Superconducting Qubits. PHYSICAL REVIEW LETTERS 2022; 128:150501. [PMID: 35499907 DOI: 10.1103/physrevlett.128.150501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 03/15/2022] [Indexed: 06/14/2023]
Abstract
Multipartite entangled states are significant resources for both quantum information processing and quantum metrology. In particular, non-Gaussian entangled states are predicted to achieve a higher sensitivity of precision measurements than Gaussian states. On the basis of metrological sensitivity, the conventional linear Ramsey squeezing parameter (RSP) efficiently characterizes the Gaussian entangled atomic states but fails for much wider classes of highly sensitive non-Gaussian states. These complex non-Gaussian entangled states can be classified by the nonlinear squeezing parameter (NLSP), as a generalization of the RSP with respect to nonlinear observables and identified via the Fisher information. However, the NLSP has never been measured experimentally. Using a 19-qubit programmable superconducting processor, we report the characterization of multiparticle entangled states generated during its nonlinear dynamics. First, selecting ten qubits, we measure the RSP and the NLSP by single-shot readouts of collective spin operators in several different directions. Then, by extracting the Fisher information of the time-evolved state of all 19 qubits, we observe a large metrological gain of 9.89_{-0.29}^{+0.28} dB over the standard quantum limit, indicating a high level of multiparticle entanglement for quantum-enhanced phase sensitivity. Benefiting from high-fidelity full controls and addressable single-shot readouts, the superconducting processor with interconnected qubits provides an ideal platform for engineering and benchmarking non-Gaussian entangled states that are useful for quantum-enhanced metrology.
Collapse
Affiliation(s)
- Kai Xu
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Yu-Ran Zhang
- Theoretical Quantum Physics Laboratory, RIKEN Cluster for Pioneering Research, Wako-shi, Saitama 351-0198, Japan
- RIKEN Center for Quantum Computing (RQC), Wako-shi, Saitama 351-0198, Japan
| | - Zheng-Hang Sun
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Hekang Li
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Pengtao Song
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Zhongcheng Xiang
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Kaixuan Huang
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Hao Li
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Yun-Hao Shi
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Chi-Tong Chen
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Xiaohui Song
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Dongning Zheng
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Franco Nori
- Theoretical Quantum Physics Laboratory, RIKEN Cluster for Pioneering Research, Wako-shi, Saitama 351-0198, Japan
- RIKEN Center for Quantum Computing (RQC), Wako-shi, Saitama 351-0198, Japan
- Physics Department, University of Michigan, Ann Arbor, Michigan 48109-1040, USA
| | - H Wang
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, and Zhejiang Province Key Laboratory of Quantum Technology and Device, Department of Physics, Zhejiang University, Hangzhou 310027, China
| | - Heng Fan
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Beijing Academy of Quantum Information Sciences and CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China
| |
Collapse
|
27
|
Esposito M, Ranadive A, Planat L, Leger S, Fraudet D, Jouanny V, Buisson O, Guichard W, Naud C, Aumentado J, Lecocq F, Roch N. Observation of Two-Mode Squeezing in a Traveling Wave Parametric Amplifier. PHYSICAL REVIEW LETTERS 2022; 128:153603. [PMID: 35499875 DOI: 10.1103/physrevlett.128.153603] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 03/18/2022] [Indexed: 06/14/2023]
Abstract
Traveling wave parametric amplifiers (TWPAs) have recently emerged as essential tools for broadband near quantum-limited amplification. However, their use to generate microwave quantum states still misses an experimental demonstration. In this Letter, we report operation of a TWPA as a source of two-mode squeezed microwave radiation. We demonstrate broadband entanglement generation between two modes separated by up to 400 MHz by measuring logarithmic negativity between 0.27 and 0.51 and collective quadrature squeezing below the vacuum limit between 1.5 and 2.1 dB. This work opens interesting perspectives for the exploration of novel microwave photonics experiments with possible applications in quantum sensing and continuous variable quantum computing.
Collapse
Affiliation(s)
- Martina Esposito
- Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France
- CNR-SPIN Complesso di Monte S. Angelo, via Cintia, Napoli 80126, Italy
| | - Arpit Ranadive
- Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France
| | - Luca Planat
- Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France
| | - Sébastien Leger
- Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France
| | - Dorian Fraudet
- Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France
| | - Vincent Jouanny
- Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France
| | - Olivier Buisson
- Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France
| | - Wiebke Guichard
- Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France
| | - Cécile Naud
- Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France
| | - José Aumentado
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - Florent Lecocq
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - Nicolas Roch
- Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France
| |
Collapse
|
28
|
Xu Z, Gao X, Bang J, Jacob Z, Li T. Non-reciprocal energy transfer through the Casimir effect. NATURE NANOTECHNOLOGY 2022; 17:148-152. [PMID: 34903895 DOI: 10.1038/s41565-021-01026-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 09/29/2021] [Indexed: 06/14/2023]
Abstract
One of the fundamental predictions of quantum mechanics is the occurrence of random fluctuations in a vacuum caused by the zero-point energy. Remarkably, quantum electromagnetic fluctuations can induce a measurable force between neutral objects, known as the Casimir effect1, and it has been studied both theoretically2,3 and experimentally4-9. The Casimir effect can dominate the interaction between microstructures at small separations and is essential for micro- and nanotechnologies10,11. It has been utilized to realize nonlinear oscillation12, quantum trapping13, phonon transfer14,15 and dissipation dilution16. However, a non-reciprocal device based on quantum vacuum fluctuations remains an unexplored frontier. Here we report quantum-vacuum-mediated non-reciprocal energy transfer between two micromechanical oscillators. We parametrically modulate the Casimir interaction to realize a strong coupling between the two oscillators with different resonant frequencies. We engineer the system's spectrum such that it possesses an exceptional point17-20 in the parameter space and explore the asymmetric topological structure in its vicinity. By dynamically changing the parameters near the exceptional point and utilizing the non-adiabaticity of the process, we achieve non-reciprocal energy transfer between the two oscillators with high contrast. Our work demonstrates a scheme that employs quantum vacuum fluctuations to regulate energy transfer at the nanoscale and may enable functional Casimir devices in the future.
Collapse
Affiliation(s)
- Zhujing Xu
- Department of Physics and Astronomy, Purdue University, West Lafayette, IN, USA
| | - Xingyu Gao
- Department of Physics and Astronomy, Purdue University, West Lafayette, IN, USA
| | - Jaehoon Bang
- School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, USA
| | - Zubin Jacob
- School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, USA
- Birck Nanotechnology Center, Purdue University, West Lafayette, IN, USA
| | - Tongcang Li
- Department of Physics and Astronomy, Purdue University, West Lafayette, IN, USA.
- School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, USA.
- Birck Nanotechnology Center, Purdue University, West Lafayette, IN, USA.
- Purdue Quantum Science and Engineering Institute, Purdue University, West Lafayette, IN, USA.
| |
Collapse
|
29
|
Butera S. Influence functional for two mirrors interacting via radiation pressure. Int J Clin Exp Med 2022. [DOI: 10.1103/physrevd.105.016023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
30
|
Statistical Physics of Evolving Systems. ENTROPY 2021; 23:e23121590. [PMID: 34945895 PMCID: PMC8700439 DOI: 10.3390/e23121590] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 11/23/2021] [Accepted: 11/24/2021] [Indexed: 11/17/2022]
Abstract
Evolution is customarily perceived as a biological process. However, when formulated in terms of physics, evolution is understood to entail everything. Based on the axiom of everything comprising quanta of actions (e.g., quanta of light), statistical physics describes any system evolving toward thermodynamic balance with its surroundings systems. Fluxes of quanta naturally select those processes leveling out differences in energy as soon as possible. This least-time maxim results in ubiquitous patterns (i.e., power laws, approximating sigmoidal cumulative curves of skewed distributions, oscillations, and even the regularity of chaos). While the equation of evolution can be written exactly, it cannot be solved exactly. Variables are inseparable since motions consume driving forces that affect motions (and so on). Thus, evolution is inherently a non-deterministic process. Yet, the future is not all arbitrary but teleological, the final cause being the least-time free energy consumption itself. Eventually, trajectories are computable when the system has evolved into a state of balance where free energy is used up altogether.
Collapse
|
31
|
Barbado LC, Báez-Camargo AL, Fuentes I. Evolution of confined quantum scalar fields in curved spacetime. Part II: Spacetimes with moving boundaries in any synchronous gauge. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2021; 81:953. [PMID: 34744505 PMCID: PMC8553737 DOI: 10.1140/epjc/s10052-021-09737-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 09/13/2021] [Accepted: 10/10/2021] [Indexed: 06/13/2023]
Abstract
We develop a method for computing the Bogoliubov transformation experienced by a confined quantum scalar field in a globally hyperbolic spacetime, due to the changes in the geometry and/or the confining boundaries. The method constructs a basis of solutions to the Klein-Gordon equation associated to each compact Cauchy hypersurface of constant time. It then provides a differential equation for the linear transformation between bases at different times. The transformation can be interpreted physically as a Bogoliubov transformation when it connects two regions in which a time symmetry allows for a Fock quantisation. This second article on the method is dedicated to spacetimes with timelike boundaries that do not remain static in any synchronous gauge. The method proves especially useful in the regime of small perturbations, where it allows one to easily make quantitative predictions on the amplitude of the resonances of the field. Therefore, it provides a crucial tool in the growing research area of confined quantum fields in table-top experiments. We prove this utility by addressing two problems in the perturbative regime: Dynamical Casimir Effect and gravitational wave resonance. We reproduce many previous results on these phenomena and find novel results in an unified way. Possible extensions of the method are indicated. We expect that our method will become standard in quantum field theory for confined fields.
Collapse
Affiliation(s)
- Luis C. Barbado
- Quantenoptik, Quantennanophysik und Quanteninformation, Fakultät für Physik, Universität Wien, Boltzmanngasse 5, 1090 Vienna, Austria
- Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der Wissenschaften, Boltzmanngasse 3, 1090 Vienna, Austria
| | - Ana L. Báez-Camargo
- Quantenoptik, Quantennanophysik und Quanteninformation, Fakultät für Physik, Universität Wien, Boltzmanngasse 5, 1090 Vienna, Austria
| | - Ivette Fuentes
- Quantenoptik, Quantennanophysik und Quanteninformation, Fakultät für Physik, Universität Wien, Boltzmanngasse 5, 1090 Vienna, Austria
- School of Mathematical Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
- School of Physics and Astronomy, University of Southampton, Southampton, SO17 1BJ UK
| |
Collapse
|
32
|
Quantum-circuit black hole lasers. Sci Rep 2021; 11:19137. [PMID: 34580347 PMCID: PMC8476520 DOI: 10.1038/s41598-021-98456-0] [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: 07/13/2021] [Accepted: 09/06/2021] [Indexed: 11/17/2022] Open
Abstract
A black hole laser in analogues of gravity amplifies Hawking radiation, which is unlikely to be measured in real black holes, and makes it observable. There have been proposals to realize such black hole lasers in various systems. However, no progress has been made in electric circuits for a long time, despite their many advantages such as high-precision electromagnetic wave detection. Here we propose a black hole laser in Josephson transmission lines incorporating metamaterial elements capable of producing Hawking-pair propagation modes and a Kerr nonlinearity due to the Josephson nonlinear inductance. A single dark soliton obeying the nonlinear Schrödinger equation produces a black hole-white hole horizon pair that acts as a laser cavity through a change in the refractive index due to the Kerr effect. We show that the resulting laser is a squeezed-state laser characterized by squeezing parameters. We also evaluate the degree of quantum correlation between Hawking and its partner radiations using entanglement entropy which does not require simultaneous measurements between them. As a result, the obtained entanglement entropy depending on the soliton velocity provides strong evidence that the resulting laser is derived from Hawking radiation with quantum correlation generated by pair production from the vacuum.
Collapse
|
33
|
Bin Q, Wu Y, Lü XY. Parity-Symmetry-Protected Multiphoton Bundle Emission. PHYSICAL REVIEW LETTERS 2021; 127:073602. [PMID: 34459658 DOI: 10.1103/physrevlett.127.073602] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Accepted: 07/09/2021] [Indexed: 06/13/2023]
Abstract
We demonstrate symmetry protected multiphoton bundle emission in the cavity QED system under the ultrastrong coupling regime. Our proposal only enables the super-Rabi oscillations with periodic generation of even correlated photons in the cavity, which is realized by combining the laser driven flip of qubit and the symmetry conserved transitions induced by Rabi interaction with parity symmetry. Combined with dissipation, only 2n-photon bundle emissions are allowed, due to the almost perfect suppression of bundle emissions with odd correlated photons. Meanwhile, the corresponding purities are significantly enhanced by the parity symmetry. This work extends multiphoton bundle emission to the ultrastrong coupling regime, and offers the prospect of exploring symmetry-protected multiphoton physics.
Collapse
Affiliation(s)
- Qian Bin
- School of Physics, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China
| | - Ying Wu
- School of Physics, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China
| | - Xin-You Lü
- School of Physics, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China
| |
Collapse
|
34
|
Sloan J, Rivera N, Joannopoulos JD, Soljačić M. Casimir Light in Dispersive Nanophotonics. PHYSICAL REVIEW LETTERS 2021; 127:053603. [PMID: 34397241 DOI: 10.1103/physrevlett.127.053603] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 05/27/2021] [Indexed: 06/13/2023]
Abstract
Time-varying optical media, whose dielectric properties are actively modulated in time, introduce a host of novel effects in the classical propagation of light, and are of intense current interest. In the quantum domain, time-dependent media can be used to convert vacuum fluctuations (virtual photons) into pairs of real photons. We refer to these processes broadly as "dynamical vacuum effects" (DVEs). Despite interest for their potential applications as sources of quantum light, DVEs are generally very weak, presenting many opportunities for enhancement through modern techniques in nanophotonics, such as using media which support excitations such as plasmon and phonon polaritons. Here, we present a theory of weakly modulated DVEs in arbitrary nanostructured, dispersive, and dissipative systems. A key element of our framework is the simultaneous incorporation of time-modulation and "dispersion" through time-translation-breaking linear response theory. As an example, we use our approach to propose a highly efficient scheme for generating entangled surface polaritons based on time-modulation of the optical phonon frequency of a polar insulator.
Collapse
Affiliation(s)
- Jamison Sloan
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Nicholas Rivera
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - John D Joannopoulos
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Marin Soljačić
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| |
Collapse
|
35
|
Kort-Kamp WJM, Azad AK, Dalvit DAR. Space-Time Quantum Metasurfaces. PHYSICAL REVIEW LETTERS 2021; 127:043603. [PMID: 34355970 DOI: 10.1103/physrevlett.127.043603] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 06/04/2021] [Indexed: 06/13/2023]
Abstract
Metasurfaces have recently entered the realm of quantum photonics, enabling manipulation of quantum light using a compact nanophotonic platform. Realizing the full potential of metasurfaces at the deepest quantum level requires the ability to tune coherent light-matter interactions continuously in space and time. Here, we introduce the concept of space-time quantum metasurfaces for arbitrary control of the spectral, spatial, and spin properties of nonclassical light using a compact photonic platform. We show that space-time quantum metasurfaces allow on-demand tailoring of entanglement among all degrees of freedom of a single photon. We also show that spatiotemporal modulation induces asymmetry at the fundamental level of quantum fluctuations, resulting in the generation of steered and vortex photon pairs out of vacuum. Space-time quantum metasurfaces have the potential to enable novel photonic functionalities, such as encoding quantum information into high-dimensional color qudits using designer modulation protocols, sculpting multispectral and multispatial modes in spontaneous emission, and generating reconfigurable hyperentanglement for high-capacity quantum communications.
Collapse
Affiliation(s)
| | - Abul K Azad
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Diego A R Dalvit
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| |
Collapse
|
36
|
Abstract
We study the motion-induced radiation due to the non-relativistic motion of an atom, coupled to the vacuum electromagnetic field by an electric dipole term, in the presence of a static graphene plate. After computing the probability of emission for an accelerated atom in empty space, we evaluate the corrections due to the presence of the plate. We show that the effect of the plate is to increase the probability of emission when the atom is near the plate and oscillates along a direction perpendicular to it. On the contrary, for parallel oscillations, there is a suppression. We also evaluate the quantum friction on an atom moving at constant velocity parallel to the plate. We show that there is a threshold for quantum friction: friction occurs only when the velocity of the atom is larger than the Fermi velocity of the electrons in graphene.
Collapse
|
37
|
Zeng X, Zubairy MS. Graphene Plasmon Excitation with Ground-State Two-Level Quantum Emitters. PHYSICAL REVIEW LETTERS 2021; 126:117401. [PMID: 33798356 DOI: 10.1103/physrevlett.126.117401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 02/22/2021] [Indexed: 06/12/2023]
Abstract
The transmission of a two-level quantum emitter in its ground state through a graphene nanosheet is investigated. The graphene plasmons (GPs) field distribution, especially the opposite orientations of the vertical electric field components on the two sides of the graphene nanosheet, produces a significant nonadiabatic process during the interaction between the emitter and the localized GPs. By taking into account the counterrotating terms, the excitation of the quantum emitter with simultaneous emission of a GP has a large probability. This happens for emitter speeds of about 10^{-4} times the speed of light. For accelerated emitters, the GPs exhibit thermal field photon distribution with a high temperature. As a consequence, this study provides a promising platform to observe the dynamical Casimir effect as well as a simulation of the Unruh effect.
Collapse
Affiliation(s)
- Xiaodong Zeng
- Department of Physics, Shanghai University, Shanghai 200444, China
- Institute for Quantum Science and Engineering (IQSE) and Department of Physics and Astronomy, Texas A&M University, College Station, Texas 77843-4242, USA
| | - M Suhail Zubairy
- Institute for Quantum Science and Engineering (IQSE) and Department of Physics and Astronomy, Texas A&M University, College Station, Texas 77843-4242, USA
| |
Collapse
|
38
|
Petukhov A. Modeling Cognitive Activity of the Human Brain by the Mathematical Apparatus of Quantum Mechanics. EPJ WEB OF CONFERENCES 2021. [DOI: 10.1051/epjconf/202124801024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
This paper discusses the possible approaches to modeling the cognitive activity of the human brain using the mathematical apparatus of quantum mechanics (primarily – potential wells and virtual particles) in terms of the theory of information representations. The article briefly describes the proposed theory of information representations, draws analogies, and identifies common features of information representations of the human mind and Feynman’s virtual particles. The human mind is represented as a one-dimensional potential well with finite walls of different sizes and internal potential barrier simulating the boundary between consciousness and subconsciousness. This creates a foundation for a mathematical apparatus that can make it possible to forecast particular cognitive functions of the human brain. The results of these studies can be used to create predictive models of various cognitive disorders (diseases) and to be used in diagnostics.
Collapse
|
39
|
Perspective on Some Recent and Future Developments in Casimir Interactions. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app11010293] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Here, we present a critical review of recent developments in Casimir physics motivated by discoveries of novel materials. Specifically, topologically nontrivial properties of the graphene family, Chern and topological insulators, and Weyl semimetals have diverse manifestations in the distance dependence, presence of fundamental constants, magnitude, and sign of the Casimir interaction. Limited studies of the role of nonlinear optical properties in the interaction are also reviewed. We show that, since many new materials have greatly enhanced the nonlinear optical response, new efficient pathways for investigation of the characteristic regimes of the Casimir force need to be explored, which are expected to lead to new discoveries. Recent progress in the dynamical Casimir effect is also reviewed and we argue that nonlinear media can open up new directions in this field as well.
Collapse
|
40
|
Mandal A, Montillo Vega S, Huo P. Polarized Fock States and the Dynamical Casimir Effect in Molecular Cavity Quantum Electrodynamics. J Phys Chem Lett 2020; 11:9215-9223. [PMID: 32991814 DOI: 10.1021/acs.jpclett.0c02399] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We present a new theoretical framework, polarized Fock states (PFSs), to describe the coupled molecule-cavity hybrid system in quantum electrodynamics. Through the quantum light-matter interactions under the dipole Gauge, the molecular permanent dipoles polarize the photon field by displacing the photonic coordinate. Hence, it is convenient to use these shifted Fock states (termed the PFSs) to describe light-matter interactions under the strong coupling regimes. These PFSs are nonorthogonal to each other and are light-matter entangled states. They allow an intuitive understanding of several phenomena that go beyond the prediction of the quantum Rabi model, while also offering numerical convenience to converge the results with much fewer states. With this powerful new theoretical framework, we explain how molecular permanent dipoles lead to the generation of multiple photons from a single electronic excitation (down-conversion), effectively achieving the dynamical Casimir effect through the nuclear vibration instead of cavity mirror oscillations.
Collapse
Affiliation(s)
- Arkajit Mandal
- Department of Chemistry, University of Rochester, Rochester, New York 14627, United States
| | | | - Pengfei Huo
- Department of Chemistry, University of Rochester, Rochester, New York 14627, United States
| |
Collapse
|
41
|
Halbhuber M, Mornhinweg J, Zeller V, Ciuti C, Bougeard D, Huber R, Lange C. Non-adiabatic stripping of a cavity field from deep-strongly coupled electrons. NATURE PHOTONICS 2020; 14:675-679. [PMID: 34221109 PMCID: PMC7611102 DOI: 10.1038/s41566-020-0673-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 06/29/2020] [Indexed: 05/15/2023]
Abstract
Atomically strong light pulses can drive sub-optical-cycle dynamics. When the Rabi frequency - the rate of energy exchange between light and matter - exceeds the optical carrier frequency, fascinating non-perturbative strong-field phenomena emerge, such as high-harmonic generation and lightwave transport. Here, we explore a related novel subcycle regime of ultimately strong light-matter interaction without a coherent driving field. We use the vacuum fluctuations of nanoantennas to drive cyclotron resonances of two-dimensional electron gases to vacuum Rabi frequencies exceeding the carrier frequency. Femtosecond photoactivation of a switch element inside the cavity disrupts this 'deep-strong coupling' more than an order of magnitude faster than the oscillation cycle of light. The abrupt modification of the vacuum ground state causes spectrally broadband polarisation oscillations confirmed by our quantum model. In the future, this subcycle shaping of hybrid quantum states may trigger cavity-induced quantum chemistry, vacuum-modified transport, or cavity-controlled superconductivity, opening new scenarios for non-adiabatic quantum optics.
Collapse
Affiliation(s)
- M Halbhuber
- Department of Physics, University of Regensburg, 93040 Regensburg, Germany
| | - J Mornhinweg
- Department of Physics, University of Regensburg, 93040 Regensburg, Germany
| | - V Zeller
- Department of Physics, University of Regensburg, 93040 Regensburg, Germany
| | - C Ciuti
- Université de Paris, Laboratoire Matériaux et Phénomènes Quantiques, CNRS, F-75013, Paris, France
| | - D Bougeard
- Department of Physics, University of Regensburg, 93040 Regensburg, Germany
| | - R Huber
- Department of Physics, University of Regensburg, 93040 Regensburg, Germany
| | - C Lange
- Department of Physics, University of Regensburg, 93040 Regensburg, Germany
| |
Collapse
|
42
|
Braidotti MC, Vinante A, Gasbarri G, Faccio D, Ulbricht H. Zel'dovich Amplification in a Superconducting Circuit. PHYSICAL REVIEW LETTERS 2020; 125:140801. [PMID: 33064533 DOI: 10.1103/physrevlett.125.140801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 07/11/2020] [Accepted: 08/18/2020] [Indexed: 06/11/2023]
Abstract
Zel'dovich proposed that electromagnetic (EM) waves with angular momentum reflected from a rotating metallic, lossy cylinder will be amplified. However, we are still lacking a direct experimental EM-wave verification of this fifty-year-old prediction due to the challenging conditions in which the phenomenon manifests itself: the mechanical rotation frequency of the cylinder must be comparable with the EM oscillation frequency. Here, we propose an experimental approach that solves this issue and is predicted to lead to a measurable Zel'dovich amplification with existing superconducting circuit technology. We design a superconducting circuit with low frequency EM modes that couple through free space to a magnetically levitated and spinning microsphere placed at the center of the circuit. We theoretically estimate the circuit EM mode gain and show that rotation of the microsphere can lead to experimentally observable amplification, thus paving the way for the first EM-field experimental demonstration of Zel'dovich amplification.
Collapse
Affiliation(s)
| | - Andrea Vinante
- Department of Physics and Astronomy, University of Southampton, SO17 1BJ Southampton, United Kingdom
- Istituto di Fotonica e Nanotecnologie-CNR and Fondazione Bruno Kessler, I-38123 Povo, Trento, Italy
| | - Giulio Gasbarri
- Department of Physics and Astronomy, University of Southampton, SO17 1BJ Southampton, United Kingdom
| | - Daniele Faccio
- School of Physics and Astronomy, University of Glasgow, G12 8QQ Glasgow, United Kingdom
| | - Hendrik Ulbricht
- Department of Physics and Astronomy, University of Southampton, SO17 1BJ Southampton, United Kingdom
| |
Collapse
|
43
|
Abstract
We propose an experimental setup to test the effect of curved spacetime upon the extraction of entanglement from the quantum field vacuum to a pair of two-level systems. We consider two superconducting qubits coupled to a dc-SQUID array embedded into an open microwave transmission line, where an external bias can emulate a spacetime containing a traversable wormhole. We find that the amount of vacuum entanglement that can be extracted by the qubits depends on the wormhole parameters. At some distances qubits which would be in a separable state in flat spacetime would become entangled due to the analogue wormhole background.
Collapse
|
44
|
Blencowe MP, Wang H. Analogue gravity on a superconducting chip. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2020; 378:20190224. [PMID: 32684136 PMCID: PMC7422880 DOI: 10.1098/rsta.2019.0224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/06/2020] [Indexed: 06/11/2023]
Abstract
We describe how analogues of a Hawking evaporating black hole as well as the Unruh effect for an oscillatory, accelerating photodetector in vacuum may be realized using superconducting, microwave circuits that are fashioned out of Josephson tunnel junction and film bulk acoustic resonator elements. This article is part of a discussion meeting issue 'The next generation of analogue gravity experiments'.
Collapse
Affiliation(s)
- Miles P. Blencowe
- Department of Physics and Astronomy, Dartmouth College, Hanover, NH 03755, USA
| | | |
Collapse
|
45
|
Wittemer M, Schröder JP, Hakelberg F, Kiefer P, Fey C, Schuetzhold R, Warring U, Schaetz T. Trapped-ion toolkit for studies of quantum harmonic oscillators under extreme conditions. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2020; 378:20190230. [PMID: 32684127 PMCID: PMC7422877 DOI: 10.1098/rsta.2019.0230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/25/2020] [Indexed: 06/11/2023]
Abstract
Many phenomena described in relativistic quantum field theory are inaccessible to direct observations, but analogue processes studied under well-defined laboratory conditions can present an alternative perspective. Recently, we demonstrated an analogy of particle creation using an intrinsically robust motional mode of two trapped atomic ions. Here, we substantially extend our classical control techniques by implementing machine-learning strategies in our platform and, consequently, increase the accessible parameter regime. As a proof of methodology, we present experimental results of multiple quenches and parametric modulation of an unprotected motional mode of a single ion, demonstrating the increased level of real-time control. In combination with previous results, we enable future experiments that may yield entanglement generation using a process in analogy to Hawking radiation. This article is part of a discussion meeting issue 'The next generation of analogue gravity experiments'.
Collapse
Affiliation(s)
- Matthias Wittemer
- Albert-Ludwigs-Universität Freiburg, Physikalisches Institut, Hermann-Herder-Strasse 3, 79104 Freiburg, Germany
| | - Jan-Philipp Schröder
- Albert-Ludwigs-Universität Freiburg, Physikalisches Institut, Hermann-Herder-Strasse 3, 79104 Freiburg, Germany
| | - Frederick Hakelberg
- Albert-Ludwigs-Universität Freiburg, Physikalisches Institut, Hermann-Herder-Strasse 3, 79104 Freiburg, Germany
| | - Philip Kiefer
- Albert-Ludwigs-Universität Freiburg, Physikalisches Institut, Hermann-Herder-Strasse 3, 79104 Freiburg, Germany
| | - Christian Fey
- Zentrum für Optische Quantentechnologien, Universität Hamburg, Fachbereich Physik, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Ralf Schuetzhold
- Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
- Institut für Theoretische Physik, Technische Universität Dresden, 01062 Dresden, Germany
| | - Ulrich Warring
- Albert-Ludwigs-Universität Freiburg, Physikalisches Institut, Hermann-Herder-Strasse 3, 79104 Freiburg, Germany
| | - Tobias Schaetz
- Albert-Ludwigs-Universität Freiburg, Physikalisches Institut, Hermann-Herder-Strasse 3, 79104 Freiburg, Germany
| |
Collapse
|
46
|
Jacquet MJ, Weinfurtner S, König F. The next generation of analogue gravity experiments. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2020; 378:20190239. [PMID: 32684138 PMCID: PMC7422886 DOI: 10.1098/rsta.2019.0239] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/07/2020] [Indexed: 06/11/2023]
Affiliation(s)
- M. J. Jacquet
- Laboratoire Kastler Brossel, Sorbonne Université, CNRS, ENS-Université PSL, Collège de France, Paris 75005, France
| | - S. Weinfurtner
- School of Mathematical Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - F. König
- School of Physics and Astronomy, SUPA, University of St Andrews, North Haugh, St Andrews KY16 9SS, UK
| |
Collapse
|
47
|
Chen L, Chang K. Chiral-Anomaly-Driven Casimir-Lifshitz Torque between Weyl Semimetals. PHYSICAL REVIEW LETTERS 2020; 125:047402. [PMID: 32794785 DOI: 10.1103/physrevlett.125.047402] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 07/08/2020] [Indexed: 06/11/2023]
Abstract
We propose a new mechanism to generate the Casimir-Lifshitz torque between Weyl semimetals arising from the chiral anomaly. For short distances ranging from a nanometer to a few tens of nanometers, chiral anomaly is manifested via a Casimir-Lifshitz torque ∼sin(θ) with θ being the twisting angle. As the distance between Weyl semimetals increases from a submicrometer to a few micrometers, chiral-anomaly-driven Casimir-Lifshitz torque between Weyl semimetals is remarkably large, which is comparable with that of conventional birefringent materials.
Collapse
Affiliation(s)
- Liang Chen
- Mathematics and Physics Department, North China Electric Power University, Beijing 102206, China
| | - Kai Chang
- SKLSM, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083, China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
| |
Collapse
|
48
|
Agustí A, Chang CWS, Quijandría F, Johansson G, Wilson CM, Sabín C. Tripartite Genuine Non-Gaussian Entanglement in Three-Mode Spontaneous Parametric Down-Conversion. PHYSICAL REVIEW LETTERS 2020; 125:020502. [PMID: 32701323 DOI: 10.1103/physrevlett.125.020502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 06/19/2020] [Indexed: 06/11/2023]
Abstract
We show that the states generated by a three-mode spontaneous parametric down-conversion (SPDC) interaction Hamiltonian possess tripartite entanglement of a different nature to other paradigmatic three-mode entangled states generated by the combination of two-mode SPDC interactions. While two-mode SPDC generates Gaussian states whose entanglement can be characterized by standard criteria based on two-mode quantum correlations, these criteria fail to capture the entanglement generated by three-mode SPDC. We use criteria built from three-mode correlation functions to show that the class of states recently generated in a superconducting-circuit implementation of three-mode SPDC ideally have tripartite entanglement, contrary to recent claims in the literature. These criteria are suitable for triple SPDC but we show that they fail to detect tripartite entanglement in other states which are known to possess it, which illustrates the existence of two fundamentally different notions of tripartite entanglement in three-mode continuous-variable systems.
Collapse
Affiliation(s)
- A Agustí
- Instituto de Física Fundamental, CSIC, Serrano, 113-bis, 28006 Madrid, Spain
| | - C W Sandbo Chang
- Institute for Quantum Computing and Electrical and Computer Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - F Quijandría
- Microtechnology and Nanoscience, MC2, Chalmers University of Technology, SE-412 96 Göteborg, Sweden
| | - G Johansson
- Microtechnology and Nanoscience, MC2, Chalmers University of Technology, SE-412 96 Göteborg, Sweden
| | - C M Wilson
- Institute for Quantum Computing and Electrical and Computer Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - C Sabín
- Instituto de Física Fundamental, CSIC, Serrano, 113-bis, 28006 Madrid, Spain
| |
Collapse
|
49
|
Zhou Y, Alam MZ, Karimi M, Upham J, Reshef O, Liu C, Willner AE, Boyd RW. Broadband frequency translation through time refraction in an epsilon-near-zero material. Nat Commun 2020; 11:2180. [PMID: 32358528 PMCID: PMC7195366 DOI: 10.1038/s41467-020-15682-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 03/19/2020] [Indexed: 11/25/2022] Open
Abstract
Space-time duality in paraxial optical wave propagation implies the existence of intriguing effects when light interacts with a material exhibiting two refractive indexes separated by a boundary in time. The direct consequence of such time-refraction effect is a change in the frequency of light while leaving the wavevector unchanged. Here, we experimentally show that the effect of time refraction is significantly enhanced in an epsilon-near-zero (ENZ) medium as a consequence of the optically induced unity-order refractive index change in a sub-picosecond time scale. Specifically, we demonstrate broadband and controllable shift (up to 14.9 THz) in the frequency of a light beam using a time-varying subwavelength-thick indium tin oxide (ITO) film in its ENZ spectral range. Our findings hint at the possibility of designing (3 + 1)D metamaterials by incorporating time-varying bulk ENZ materials, and they present a unique playground to investigate various novel effects in the time domain. Here, the authors present an experimental demonstration of adiabatic frequency conversion using the concept of time boundary by exploiting the properties of an ITO film operating near its epsilon-near-zero frequency. They demonstrate a large and controllable shift up to 14.9 THz.
Collapse
Affiliation(s)
- Yiyu Zhou
- The Institute of Optics, University of Rochester, Rochester, NY, 14627, USA.
| | - M Zahirul Alam
- Department of Physics, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
| | - Mohammad Karimi
- Department of Physics, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
| | - Jeremy Upham
- Department of Physics, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
| | - Orad Reshef
- Department of Physics, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
| | - Cong Liu
- Department of Electrical Engineering, University of Southern California, Los Angeles, CA, 90089, USA
| | - Alan E Willner
- Department of Electrical Engineering, University of Southern California, Los Angeles, CA, 90089, USA
| | - Robert W Boyd
- The Institute of Optics, University of Rochester, Rochester, NY, 14627, USA.,Department of Physics, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
| |
Collapse
|
50
|
Schneider BH, Bengtsson A, Svensson IM, Aref T, Johansson G, Bylander J, Delsing P. Observation of Broadband Entanglement in Microwave Radiation from a Single Time-Varying Boundary Condition. PHYSICAL REVIEW LETTERS 2020; 124:140503. [PMID: 32338986 DOI: 10.1103/physrevlett.124.140503] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2018] [Revised: 02/28/2020] [Accepted: 03/27/2020] [Indexed: 06/11/2023]
Abstract
Entangled pairs of microwave photons are commonly produced in the narrow frequency band of a resonator, which represents a modified vacuum density of states. We generate and investigate the entanglement of a stream of photon pairs, generated in a semi-infinite broadband transmission line, terminated by a superconducting quantum interference device (SQUID). A weak pump signal modulates the SQUID inductance, resulting in a single time-varying boundary condition, and we detect all four quadratures of the microwave radiation emitted at two different frequencies separated by 0.7 GHz. Power calibration is done in situ, and we find positive logarithmic negativity and two-mode squeezing below the vacuum in the observed radiation, indicating entanglement.
Collapse
Affiliation(s)
- B H Schneider
- Department of Microtechnology and Nanoscience (MC2), Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
| | - A Bengtsson
- Department of Microtechnology and Nanoscience (MC2), Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
| | - I M Svensson
- Department of Microtechnology and Nanoscience (MC2), Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
| | - T Aref
- Department of Microtechnology and Nanoscience (MC2), Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
| | - G Johansson
- Department of Microtechnology and Nanoscience (MC2), Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
| | - Jonas Bylander
- Department of Microtechnology and Nanoscience (MC2), Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
| | - P Delsing
- Department of Microtechnology and Nanoscience (MC2), Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
| |
Collapse
|