1
|
Kongkhambut P, Cosme JG, Skulte J, Moreno Armijos MA, Mathey L, Hemmerich A, Keßler H. Observation of a phase transition from a continuous to a discrete time crystal. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2024; 87:080502. [PMID: 39029474 DOI: 10.1088/1361-6633/ad6585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 07/16/2024] [Indexed: 07/21/2024]
Abstract
Discrete (DTCs) and continuous time crystals (CTCs) are novel dynamical many-body states, that are characterized by robust self-sustained oscillations, emerging via spontaneous breaking of discrete or continuous time translation symmetry. DTCs are periodically driven systems that oscillate with a subharmonic of the external drive, while CTCs are continuously driven and oscillate with a frequency intrinsic to the system. Here, we explore a phase transition from a continuous time crystal to a discrete time crystal. A CTC with a characteristic oscillation frequencyωCTCis prepared in a continuously pumped atom-cavity system. Modulating the pump intensity of the CTC with a frequencyωdrclose to2ωCTCleads to robust locking ofωCTCtoωdr/2, and hence a DTC arises. This phase transition in a quantum many-body system is related to subharmonic injection locking of non-linear mechanical and electronic oscillators or lasers.
Collapse
Affiliation(s)
- Phatthamon Kongkhambut
- Zentrum für Optische Quantentechnologien and Institut für Quantenphysik, Universität Hamburg, 22761 Hamburg, Germany
| | - Jayson G Cosme
- National Institute of Physics, University of the Philippines, Diliman, Quezon City 1101, Philippines
| | - Jim Skulte
- Zentrum für Optische Quantentechnologien and Institut für Quantenphysik, Universität Hamburg, 22761 Hamburg, Germany
- The Hamburg Center for Ultrafast Imaging, 22761 Hamburg, Germany
| | | | - Ludwig Mathey
- Zentrum für Optische Quantentechnologien and Institut für Quantenphysik, Universität Hamburg, 22761 Hamburg, Germany
- The Hamburg Center for Ultrafast Imaging, 22761 Hamburg, Germany
| | - Andreas Hemmerich
- Zentrum für Optische Quantentechnologien and Institut für Quantenphysik, Universität Hamburg, 22761 Hamburg, Germany
- The Hamburg Center for Ultrafast Imaging, 22761 Hamburg, Germany
| | - Hans Keßler
- Zentrum für Optische Quantentechnologien and Institut für Quantenphysik, Universität Hamburg, 22761 Hamburg, Germany
- Physikalisches Institut, Rheinische Friedrich-Wilhelms-Universität, 53115 Bonn, Germany
| |
Collapse
|
2
|
Cooper A, Olivieri L, Cutrona A, Das D, Peters L, Chu ST, Little B, Morandotti R, Moss DJ, Peccianti M, Pasquazi A. Parametric interaction of laser cavity-solitons with an external CW pump. OPTICS EXPRESS 2024; 32:21783-21794. [PMID: 38859524 DOI: 10.1364/oe.524838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Accepted: 05/05/2024] [Indexed: 06/12/2024]
Abstract
We study the interaction of a laser cavity-soliton microcomb with an externally coupled, co-propagating tunable CW pump, observing parametric Kerr interactions which lead to the formation of both a cross-phase modulation and a four-wave mixing replica of the laser cavity-soliton. We compare and explain the dependence of the microcomb spectra from both the cavity-soliton and pump parameters, demonstrating the ability to adjust the microcomb externally without breaking or interfering with the soliton state. The parametric nature of the process agrees with numerical simulations. The parametric extended state maintains the typical robustness of laser-cavity solitons.
Collapse
|
3
|
Carraro-Haddad I, Chafatinos DL, Kuznetsov AS, Papuccio-Fernández IA, Reynoso AA, Bruchhausen A, Biermann K, Santos PV, Usaj G, Fainstein A. Solid-state continuous time crystal in a polariton condensate with a built-in mechanical clock. Science 2024; 384:995-1000. [PMID: 38815032 DOI: 10.1126/science.adn7087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2023] [Accepted: 04/18/2024] [Indexed: 06/01/2024]
Abstract
Time crystals (TCs) are many-body systems that display spontaneous breaking of time translation symmetry. We demonstrate a TC by using driven-dissipative condensates of microcavity exciton-polaritons, spontaneously formed from an incoherent particle bath. The TC phases are controlled by the power of a continuous-wave nonresonant optical drive exciting the condensate and the interaction with cavity phonons. Those phases are, for increasing power, Larmor-like precession of the condensate pseudo-spins-a signature of continuous TC; locking of the frequency of precession to self-sustained coherent phonons-stabilized TC; and doubling of TC's period by phonons-a discrete TC with continuous excitation. These results establish microcavity polaritons as a platform for the investigation of time-broken symmetry in nonhermitian systems.
Collapse
Affiliation(s)
- I Carraro-Haddad
- Centro Atómico Bariloche and Instituto Balseiro, Comisión Nacional de Energía Atómica (CNEA)-Universidad Nacional de Cuyo (UNCUYO), Bariloche 8400, Argentina
- Instituto de Nanociencia y Nanotecnología (INN-Bariloche), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bariloche 8400, Argentina
| | - D L Chafatinos
- Centro Atómico Bariloche and Instituto Balseiro, Comisión Nacional de Energía Atómica (CNEA)-Universidad Nacional de Cuyo (UNCUYO), Bariloche 8400, Argentina
- Instituto de Nanociencia y Nanotecnología (INN-Bariloche), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bariloche 8400, Argentina
| | - A S Kuznetsov
- Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund 10117 Berlin e.V., 10117 Berlin, Germany
| | - I A Papuccio-Fernández
- Centro Atómico Bariloche and Instituto Balseiro, Comisión Nacional de Energía Atómica (CNEA)-Universidad Nacional de Cuyo (UNCUYO), Bariloche 8400, Argentina
- Instituto de Nanociencia y Nanotecnología (INN-Bariloche), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bariloche 8400, Argentina
| | - A A Reynoso
- Centro Atómico Bariloche and Instituto Balseiro, Comisión Nacional de Energía Atómica (CNEA)-Universidad Nacional de Cuyo (UNCUYO), Bariloche 8400, Argentina
- Instituto de Nanociencia y Nanotecnología (INN-Bariloche), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bariloche 8400, Argentina
| | - A Bruchhausen
- Centro Atómico Bariloche and Instituto Balseiro, Comisión Nacional de Energía Atómica (CNEA)-Universidad Nacional de Cuyo (UNCUYO), Bariloche 8400, Argentina
- Instituto de Nanociencia y Nanotecnología (INN-Bariloche), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bariloche 8400, Argentina
| | - K Biermann
- Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund 10117 Berlin e.V., 10117 Berlin, Germany
| | - P V Santos
- Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund 10117 Berlin e.V., 10117 Berlin, Germany
| | - G Usaj
- Centro Atómico Bariloche and Instituto Balseiro, Comisión Nacional de Energía Atómica (CNEA)-Universidad Nacional de Cuyo (UNCUYO), Bariloche 8400, Argentina
- Instituto de Nanociencia y Nanotecnología (INN-Bariloche), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bariloche 8400, Argentina
- Theorie van Kwantumsystemen en Complexe Systemen (TQC), Universiteit Antwerpen, B-2610 Antwerpen, Belgium
- CENOLI, Université Libre de Bruxelles-CP 231, B-1050 Brussels, Belgium
| | - A Fainstein
- Centro Atómico Bariloche and Instituto Balseiro, Comisión Nacional de Energía Atómica (CNEA)-Universidad Nacional de Cuyo (UNCUYO), Bariloche 8400, Argentina
- Instituto de Nanociencia y Nanotecnología (INN-Bariloche), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bariloche 8400, Argentina
| |
Collapse
|
4
|
Li Y, Wang C, Tang Y, Liu YC. Time Crystal in a Single-Mode Nonlinear Cavity. PHYSICAL REVIEW LETTERS 2024; 132:183803. [PMID: 38759188 DOI: 10.1103/physrevlett.132.183803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 01/22/2024] [Accepted: 04/08/2024] [Indexed: 05/19/2024]
Abstract
Time crystal is a class of nonequilibrium phases with broken time-translational symmetry. Here, we demonstrate the time crystal in a single-mode nonlinear cavity. The time crystal originates from the self-oscillation induced by a linear gain and is stabilized by a nonlinear damping. We show in the time crystal phase there are sharp dissipative gap closing and pure imaginary eigenvalues of the Liouvillian spectrum in the thermodynamic limit. Dynamically, we observe a metastable regime with the emergence of quantum oscillation, followed by a dissipative evolution with a timescale much longer than the oscillating period. Moreover, we show there is a dissipative phase transition at the Hopf bifurcation, which can be characterized by the photon number fluctuation in the steady state. These results pave a new promising way for further experiments and deepen our understanding of time crystals.
Collapse
Affiliation(s)
- Yaohua Li
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Chenyang Wang
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Yuanjiang Tang
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Yong-Chun Liu
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
- Frontier Science Center for Quantum Information, Beijing 100084, China
| |
Collapse
|
5
|
Mukherjee V, Divakaran U. The promises and challenges of many-body quantum technologies: A focus on quantum engines. Nat Commun 2024; 15:3170. [PMID: 38609387 PMCID: PMC11014963 DOI: 10.1038/s41467-024-47638-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 04/08/2024] [Indexed: 04/14/2024] Open
Affiliation(s)
- Victor Mukherjee
- Department of Physical Sciences, Indian Institute of Science Education and Research Berhampur, Berhampur, 760010, India.
| | - Uma Divakaran
- Department of Physics, Indian Institute of Technology Palakkad, Palakkad, Kerala, 678623, India
| |
Collapse
|
6
|
Moille G, Stone J, Chojnacky M, Shrestha R, Javid UA, Menyuk C, Srinivasan K. Kerr-induced synchronization of a cavity soliton to an optical reference. Nature 2023; 624:267-274. [PMID: 38092906 DOI: 10.1038/s41586-023-06730-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 10/09/2023] [Indexed: 12/18/2023]
Abstract
The phase-coherent frequency division of a stabilized optical reference laser to the microwave domain is made possible by optical-frequency combs (OFCs)1,2. OFC-based clockworks3-6 lock one comb tooth to a reference laser, which probes a stable atomic transition, usually through an active servo that increases the complexity of the OFC photonic and electronic integration for fieldable clock applications. Here, we demonstrate that the Kerr nonlinearity enables passive, electronics-free synchronization of a microresonator-based dissipative Kerr soliton (DKS) OFC7 to an externally injected reference laser. We present a theoretical model explaining this Kerr-induced synchronization (KIS), which closely matches experimental results based on a chip-integrated, silicon nitride, micro-ring resonator. Once synchronized, the reference laser captures an OFC tooth, so that tuning its frequency provides direct external control of the OFC repetition rate. We also show that the stability of the repetition rate is linked to that of the reference laser through the expected frequency division factor. Finally, KIS of an octave-spanning DKS exhibits enhancement of the opposite dispersive wave, consistent with the theoretical model, and enables improved self-referencing and access to the OFC carrier-envelope offset frequency. The KIS-mediated enhancements we demonstrate can be directly implemented in integrated optical clocks and chip-scale low-noise microwave generators.
Collapse
Affiliation(s)
- Grégory Moille
- Joint Quantum Institute, NIST/University of Maryland, College Park, MD, USA.
- Microsystems and Nanotechnology Division, National Institute of Standards and Technology, Gaithersburg, MD, USA.
| | - Jordan Stone
- Joint Quantum Institute, NIST/University of Maryland, College Park, MD, USA
- Microsystems and Nanotechnology Division, National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - Michal Chojnacky
- Joint Quantum Institute, NIST/University of Maryland, College Park, MD, USA
- Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - Rahul Shrestha
- Joint Quantum Institute, NIST/University of Maryland, College Park, MD, USA
| | - Usman A Javid
- Joint Quantum Institute, NIST/University of Maryland, College Park, MD, USA
- Microsystems and Nanotechnology Division, National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - Curtis Menyuk
- University of Maryland at Baltimore County, Baltimore, MD, USA
| | - Kartik Srinivasan
- Joint Quantum Institute, NIST/University of Maryland, College Park, MD, USA.
- Microsystems and Nanotechnology Division, National Institute of Standards and Technology, Gaithersburg, MD, USA.
| |
Collapse
|
7
|
Machado F, Zhuang Q, Yao NY, Zaletel MP. Absolutely Stable Time Crystals at Finite Temperature. PHYSICAL REVIEW LETTERS 2023; 131:180402. [PMID: 37977624 DOI: 10.1103/physrevlett.131.180402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 07/27/2023] [Accepted: 09/07/2023] [Indexed: 11/19/2023]
Abstract
We show that locally interacting, periodically driven (Floquet) Hamiltonian dynamics coupled to a Langevin bath support finite-temperature discrete time crystals (DTCs) with an infinite autocorrelation time. By contrast to both prethermal and many-body localized DTCs, the time crystalline order we uncover is stable to arbitrary perturbations, including those that break the time translation symmetry of the underlying drive. Our approach utilizes a general mapping from probabilistic cellular automata to open classical Floquet systems undergoing continuous-time Langevin dynamics. Applying this mapping to a variant of the Toom cellular automaton, which we dub the "π-Toom time crystal," leads to a 2D Floquet Hamiltonian with a finite-temperature DTC phase transition. We provide numerical evidence for the existence of this transition, and analyze the statistics of the finite temperature fluctuations. Finally, we discuss how general results from the field of probabilistic cellular automata imply the existence of discrete time crystals (with an infinite autocorrelation time) in all dimensions, d≥1.
Collapse
Affiliation(s)
- Francisco Machado
- ITAMP, Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, USA
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Department of Physics, University of California, Berkeley, Berkeley, California 94720, USA
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Quntao Zhuang
- Department of Physics, University of California, Berkeley, Berkeley, California 94720, USA
- James C. Wyant College of Optical Sciences, University of Arizona, Tucson, Arizona 85721, USA
- Ming Hsieh Department of Electrical and Computer Engineering and Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089, USA
| | - Norman Y Yao
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Department of Physics, University of California, Berkeley, Berkeley, California 94720, USA
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Michael P Zaletel
- Department of Physics, University of California, Berkeley, Berkeley, California 94720, USA
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| |
Collapse
|
8
|
Chen YH, Zhang X. Realization of an inherent time crystal in a dissipative many-body system. Nat Commun 2023; 14:6161. [PMID: 37789006 PMCID: PMC10547780 DOI: 10.1038/s41467-023-41905-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Accepted: 09/21/2023] [Indexed: 10/05/2023] Open
Abstract
Time crystals are many-body states that spontaneously break translation symmetry in time the way that ordinary crystals do in space. While experimental observations have confirmed the existence of discrete or continuous time crystals, these realizations have relied on the utilization of periodic forces or effective modulation through cavity feedback. The original proposal for time crystals is that they would represent self-sustained motions without any external periodicity, but realizing such purely self-generated behavior has not yet been achieved. Here, we provide theoretical and experimental evidence that many-body interactions can give rise to an inherent time crystalline phase. Following a calculation that shows an ensemble of pumped four-level atoms can spontaneously break continuous time translation symmetry, we observe periodic motions in an erbium-doped solid. The inherent time crystal produced by our experiment is self-protected by many-body interactions and has a measured coherence time beyond that of individual erbium ions.
Collapse
Affiliation(s)
- Yu-Hui Chen
- Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurements of Ministry of Education, School of Physics, Beijing Institute of Technology, 100081, Beijing, China
- Beijing Key Laboratory of Nanophotonics & Ultrafine Optoelectronic Systems, School of Physics, Beijing Institute of Technology, 100081, Beijing, China
| | - Xiangdong Zhang
- Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurements of Ministry of Education, School of Physics, Beijing Institute of Technology, 100081, Beijing, China.
- Beijing Key Laboratory of Nanophotonics & Ultrafine Optoelectronic Systems, School of Physics, Beijing Institute of Technology, 100081, Beijing, China.
| |
Collapse
|
9
|
Krishna M, Solanki P, Hajdušek M, Vinjanampathy S. Measurement-Induced Continuous Time Crystals. PHYSICAL REVIEW LETTERS 2023; 130:150401. [PMID: 37115890 DOI: 10.1103/physrevlett.130.150401] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 03/13/2023] [Indexed: 06/19/2023]
Abstract
Strong measurements usually restrict the dynamics of measured finite dimensional systems to the Zeno subspace, where subsequent evolution is unitary due to the suppression of dissipative terms. Here, we show qualitatively different behavior induced by the competition between strong measurements and the thermodynamic limit, inducing a time-translation symmetry breaking phase transition resulting in a continuous time crystal. We consider an undriven spin star model, where the central spin is subject to a strong continuous measurement, and qualify the dynamic behavior of the system in various parameter regimes. We show that above a critical value of measurement strength, the magnetization of the thermodynamically large ancilla spins, along with the central spin, develops limit-cycle oscillations.
Collapse
Affiliation(s)
- Midhun Krishna
- Department of Physics, Indian Institute of Technology-Bombay, Powai, Mumbai 400076, India
| | - Parvinder Solanki
- Department of Physics, Indian Institute of Technology-Bombay, Powai, Mumbai 400076, India
| | - Michal Hajdušek
- Keio University Shonan Fujisawa Campus, 5322 Endo, Fujisawa, Kanagawa 252-0882, Japan
- Keio University Quantum Computing Center, 3-14-1 Hiyoshi, Kohoku, Yokohama, Kanagawa 223-8522, Japan
| | - Sai Vinjanampathy
- Department of Physics, Indian Institute of Technology-Bombay, Powai, Mumbai 400076, India
- Centre of Excellence in Quantum Information, Computation, Science and Technology, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
- Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543 Singapore, Singapore
| |
Collapse
|
10
|
Stroganov A, Kovalev AV, Viktorov EA. Subharmonic locking and frequency combs in frequency-swept semiconductor lasers. Phys Rev E 2023; 107:034208. [PMID: 37072951 DOI: 10.1103/physreve.107.034208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Accepted: 02/28/2023] [Indexed: 04/20/2023]
Abstract
We analyze a delay differential equation model for a swept semiconductor laser and demonstrate existence of various periodic solutions that are subharmonically locked to the sweep rate. These solutions provide optical frequency combs in spectral domain. We investigate the problem numerically and show that, due to the translational symmetry of the model, there exists a hysteresis loop formed by branches of steady states solutions, bridges of periodic solutions connecting stable and unstable steady state branches, and isolated branches of limit cycles. We discuss the role of bifurcation points and limit cycles embedded into the loop in the formation of the subharmonic dynamics.
Collapse
Affiliation(s)
- A Stroganov
- ITMO University, Birzhevaya Liniya 14, Saint Petersburg 199034, Russia
| | - A V Kovalev
- ITMO University, Birzhevaya Liniya 14, Saint Petersburg 199034, Russia
| | - E A Viktorov
- ITMO University, Birzhevaya Liniya 14, Saint Petersburg 199034, Russia
| |
Collapse
|
11
|
Matsko AB, Maleki L. Low threshold Kerr solitons. OPTICS LETTERS 2023; 48:715-718. [PMID: 36723571 DOI: 10.1364/ol.479572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Accepted: 12/02/2022] [Indexed: 06/18/2023]
Abstract
Pumping a nonlinear optical cavity with continuous wave coherent light can result in generation of a stable train of short optical pulses. Pumping the cavity with a non-degenerate resonant coherent dichromatic pump usually does not produce a stable mode-locked regime due to competition of the oscillations at the pump frequencies. We show that generation of stable optical pulses is feasible in a dichromatically pumped cavity characterized with group velocity dispersion optimized in a way that the group velocity value becomes identical for the generated pulses and the beat note of the pump harmonics. The power threshold of the process drops nearly four times in this case and the produced pulses become sub-harmonically locked to the dichromatic pump harmonics. The process is useful for generation of broadband optical frequency combs and optical time crystals.
Collapse
|
12
|
Kongkhambut P, Skulte J, Mathey L, Cosme JG, Hemmerich A, Keßler H. Observation of a continuous time crystal. Science 2022; 377:670-673. [PMID: 35679353 DOI: 10.1126/science.abo3382] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Time crystals are classified as discrete or continuous depending on whether they spontaneously break discrete or continuous time translation symmetry. While discrete time crystals have been extensively studied in periodically driven systems, the experimental realization of a continuous time crystal is still pending. We report the observation of a limit cycle phase in a continuously pumped dissipative atom-cavity system, that is characterized by emergent oscillations in the intracavity photon number. The phase of the oscillation found to be random for different realizations, and hence this dynamical many-body state breaks continuous time translation symmetry spontaneously. Furthermore, the observed limit cycles are robust against temporal perturbations and therefore demonstrate the realization of a continuous time crystal.
Collapse
Affiliation(s)
- Phatthamon Kongkhambut
- Zentrum für Optische Quantentechnologien and Institut für Laser-Physik, Universität Hamburg, 22761 Hamburg, Germany
| | - Jim Skulte
- Zentrum für Optische Quantentechnologien and Institut für Laser-Physik, Universität Hamburg, 22761 Hamburg, Germany.,The Hamburg Center for Ultrafast Imaging, 22761 Hamburg, Germany
| | - Ludwig Mathey
- Zentrum für Optische Quantentechnologien and Institut für Laser-Physik, Universität Hamburg, 22761 Hamburg, Germany.,The Hamburg Center for Ultrafast Imaging, 22761 Hamburg, Germany
| | - Jayson G Cosme
- National Institute of Physics, University of the Philippines, Diliman, Quezon City 1101, Philippines
| | - Andreas Hemmerich
- Zentrum für Optische Quantentechnologien and Institut für Laser-Physik, Universität Hamburg, 22761 Hamburg, Germany.,The Hamburg Center for Ultrafast Imaging, 22761 Hamburg, Germany
| | - Hans Keßler
- Zentrum für Optische Quantentechnologien and Institut für Laser-Physik, Universität Hamburg, 22761 Hamburg, Germany
| |
Collapse
|
13
|
Tiana-Alsina J, Masoller C. Time crystal dynamics in a weakly modulated stochastic time delayed system. Sci Rep 2022; 12:4914. [PMID: 35318359 PMCID: PMC8940923 DOI: 10.1038/s41598-022-08776-y] [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: 12/15/2021] [Accepted: 02/22/2022] [Indexed: 11/20/2022] Open
Abstract
Time crystal oscillations in interacting, periodically driven many-particle systems are highly regular oscillations that persist for long periods of time, are robust to perturbations, and whose frequency differs from the frequency of the driving signal. Making use of underlying similarities of spatially-extended systems and time-delayed systems (TDSs), we present an experimental demonstration of time-crystal-like behavior in a stochastic, weakly modulated TDS. We consider a semiconductor laser near threshold with delayed feedback, whose output intensity shows abrupt spikes at irregular times. When the laser current is driven with a small-amplitude periodic signal we show that the interaction of delayed feedback and modulation can generate long-range regularity in the timing of the spikes, which lock to the modulation and, despite the presence of noise, remain in phase over thousands of modulation cycles. With pulsed modulation we find harmonic and subharmonic locking, while with sinusoidal modulation, we find only subharmonic locking, which is a characteristic feature of time-crystal behavior.
Collapse
Affiliation(s)
- Jordi Tiana-Alsina
- Department de Física Aplicada, Facultat de Fisica, Universitat de Barcelona, Marti i Franques 1, 08028, Barcelona, Spain
| | - Cristina Masoller
- Departament de Fisica, Universitat Politecnica de Catalunya, Rambla Sant Nebridi 22, 08222, Terrassa, Barcelona, Spain.
| |
Collapse
|