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Zhu GL, Hu CS, Wang H, Qin W, Lü XY, Nori F. Nonreciprocal Superradiant Phase Transitions and Multicriticality in a Cavity QED System. PHYSICAL REVIEW LETTERS 2024; 132:193602. [PMID: 38804940 DOI: 10.1103/physrevlett.132.193602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 02/06/2024] [Accepted: 04/01/2024] [Indexed: 05/29/2024]
Abstract
We demonstrate the emergence of nonreciprocal superradiant phase transitions and novel multicriticality in a cavity quantum electrodynamics system, where a two-level atom interacts with two counterpropagating modes of a whispering-gallery-mode microcavity. The cavity rotates at a certain angular velocity and is directionally squeezed by a unidirectional parametric pumping χ^{(2)} nonlinearity. The combination of cavity rotation and directional squeezing leads to nonreciprocal first- and second-order superradiant phase transitions. These transitions do not require ultrastrong atom-field couplings and can be easily controlled by the external pump field. Through a full quantum description of the system Hamiltonian, we identify two types of multicritical points in the phase diagram, both of which exhibit controllable nonreciprocity. These results open a new door for all-optical manipulation of superradiant transitions and multicritical behaviors in light-matter systems, with potential applications in engineering various integrated nonreciprocal quantum devices.
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Affiliation(s)
- Gui-Lei Zhu
- Department of Physics, Zhejiang Sci-Tech University, Hangzhou 310018, China
- Theoretical Quantum Physics Laboratory, Cluster for Pioneering Research, RIKEN, Wakoshi, Saitama 351-0198, Japan
| | - Chang-Sheng Hu
- Department of Physics, Anhui Normal University, Wuhu 241000, China
| | - Hui Wang
- Theoretical Quantum Physics Laboratory, Cluster for Pioneering Research, RIKEN, Wakoshi, Saitama 351-0198, Japan
| | - Wei Qin
- Theoretical Quantum Physics Laboratory, Cluster for Pioneering Research, RIKEN, Wakoshi, Saitama 351-0198, Japan
- Center for Joint Quantum Studies and Department of Physics, School of Science, Tianjin University, Tianjin 300350, China
| | - Xin-You Lü
- School of Physics, Huazhong University of Science and Technology and Wuhan Institute of Quantum Technology, Wuhan 430074, China
| | - Franco Nori
- Theoretical Quantum Physics Laboratory, Cluster for Pioneering Research, RIKEN, Wakoshi, Saitama 351-0198, Japan
- Quantum Computing Center, RIKEN, Wakoshi, Saitama 351-0198, Japan
- Department of Physics, The University of Michigan, Ann Arbor, Michigan 48109-1040, USA
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2
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Bohr EA, Kristensen SL, Hotter C, Schäffer SA, Robinson-Tait J, Thomsen JW, Zelevinsky T, Ritsch H, Müller JH. Collectively enhanced Ramsey readout by cavity sub- to superradiant transition. Nat Commun 2024; 15:1084. [PMID: 38316781 PMCID: PMC10844618 DOI: 10.1038/s41467-024-45420-x] [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: 07/12/2023] [Accepted: 01/22/2024] [Indexed: 02/07/2024] Open
Abstract
When an inverted ensemble of atoms is tightly packed on the scale of its emission wavelength or when the atoms are collectively strongly coupled to a single cavity mode, their dipoles will align and decay rapidly via a superradiant burst. However, a spread-out dipole phase distribution theory predicts a required minimum threshold of atomic excitation for superradiance to occur. Here we experimentally confirm this predicted threshold for superradiant emission on a narrow optical transition when exciting the atoms transversely and show how to take advantage of the resulting sub- to superradiant transition. A π/2-pulse places the atoms in a subradiant state, protected from collective cavity decay, which we exploit during the free evolution period in a corresponding Ramsey pulse sequence. The final excited state population is read out via superradiant emission from the inverted atomic ensemble after a second π/2-pulse, and with minimal heating this allows for multiple Ramsey sequences within one experimental cycle. Our scheme is an innovative approach to atomic state readout characterized by its speed, simplicity, and highly directional emission of signal photons. It demonstrates the potential of sensors using collective effects in cavity-coupled quantum emitters.
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Affiliation(s)
- Eliot A Bohr
- Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, Copenhagen, DK-2100, Denmark.
| | - Sofus L Kristensen
- Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, Copenhagen, DK-2100, Denmark
| | - Christoph Hotter
- Institut für Theoretische Physik, Universität Innsbruck, Technikerstr. 21a, Innsbruck, A-6020, Austria
| | - Stefan A Schäffer
- Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, Copenhagen, DK-2100, Denmark
| | - Julian Robinson-Tait
- Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, Copenhagen, DK-2100, Denmark
| | - Jan W Thomsen
- Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, Copenhagen, DK-2100, Denmark
| | - Tanya Zelevinsky
- Department of Physics, Columbia University, 538 West 120th Street, New York, 10027-5255, NY, USA
| | - Helmut Ritsch
- Institut für Theoretische Physik, Universität Innsbruck, Technikerstr. 21a, Innsbruck, A-6020, Austria
| | - Jörg H Müller
- Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, Copenhagen, DK-2100, Denmark
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3
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Sundar B, Barberena D, Rey AM, Orioli AP. Squeezing Multilevel Atoms in Dark States via Cavity Superradiance. PHYSICAL REVIEW LETTERS 2024; 132:033601. [PMID: 38307070 DOI: 10.1103/physrevlett.132.033601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 08/13/2023] [Accepted: 09/19/2023] [Indexed: 02/04/2024]
Abstract
We describe a method to create and store scalable and long-lived entangled spin-squeezed states within a manifold of many-body cavity dark states using collective emission of light from multilevel atoms inside an optical cavity. We show that the system can be tuned to generate squeezing in a dark state where it will be immune to superradiance. We also show more generically that squeezing can be generated using a combination of superradiance and coherent driving in a bright state, and subsequently be transferred via single-particle rotations to a dark state where squeezing can be stored. Our findings, readily testable in current optical cavity experiments with alkaline-earth-like atoms, can open a path for dissipative generation and storage of metrologically useful states in optical transitions.
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Affiliation(s)
- Bhuvanesh Sundar
- JILA, NIST, Department of Physics, University of Colorado, Boulder, Colorado 80309, USA and Center for Theory of Quantum Matter, University of Colorado, Boulder, Colorado 80309, USA
| | - Diego Barberena
- JILA, NIST, Department of Physics, University of Colorado, Boulder, Colorado 80309, USA and Center for Theory of Quantum Matter, University of Colorado, Boulder, Colorado 80309, USA
| | - Ana Maria Rey
- JILA, NIST, Department of Physics, University of Colorado, Boulder, Colorado 80309, USA and Center for Theory of Quantum Matter, University of Colorado, Boulder, Colorado 80309, USA
| | - Asier Piñeiro Orioli
- JILA, NIST, Department of Physics, University of Colorado, Boulder, Colorado 80309, USA and Center for Theory of Quantum Matter, University of Colorado, Boulder, Colorado 80309, USA
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4
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Young DJ, Chu A, Song EY, Barberena D, Wellnitz D, Niu Z, Schäfer VM, Lewis-Swan RJ, Rey AM, Thompson JK. Observing dynamical phases of BCS superconductors in a cavity QED simulator. Nature 2024; 625:679-684. [PMID: 38267683 DOI: 10.1038/s41586-023-06911-x] [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: 06/21/2023] [Accepted: 11/29/2023] [Indexed: 01/26/2024]
Abstract
In conventional Bardeen-Cooper-Schrieffer superconductors1, electrons with opposite momenta bind into Cooper pairs due to an attractive interaction mediated by phonons in the material. Although superconductivity naturally emerges at thermal equilibrium, it can also emerge out of equilibrium when the system parameters are abruptly changed2-8. The resulting out-of-equilibrium phases are predicted to occur in real materials and ultracold fermionic atoms, but not all have yet been directly observed. Here we realize an alternative way to generate the proposed dynamical phases using cavity quantum electrodynamics (QED). Our system encodes the presence or absence of a Cooper pair in a long-lived electronic transition in 88Sr atoms coupled to an optical cavity and represents interactions between electrons as photon-mediated interactions through the cavity9,10. To fully explore the phase diagram, we manipulate the ratio between the single-particle dispersion and the interactions after a quench and perform real-time tracking of the subsequent dynamics of the superconducting order parameter using nondestructive measurements. We observe regimes in which the order parameter decays to zero (phase I)3,4, assumes a non-equilibrium steady-state value (phase II)2,3 or exhibits persistent oscillations (phase III)2,3. This opens up exciting prospects for quantum simulation, including the potential to engineer unconventional superconductors and to probe beyond mean-field effects like the spectral form factor11,12, and for increasing the coherence time for quantum sensing.
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Affiliation(s)
- Dylan J Young
- JILA, NIST, and Department of Physics, University of Colorado, Boulder, CO, USA
| | - Anjun Chu
- JILA, NIST, and Department of Physics, University of Colorado, Boulder, CO, USA
- Center for Theory of Quantum Matter, University of Colorado, Boulder, CO, USA
| | - Eric Yilun Song
- JILA, NIST, and Department of Physics, University of Colorado, Boulder, CO, USA
| | - Diego Barberena
- JILA, NIST, and Department of Physics, University of Colorado, Boulder, CO, USA
- Center for Theory of Quantum Matter, University of Colorado, Boulder, CO, USA
| | - David Wellnitz
- JILA, NIST, and Department of Physics, University of Colorado, Boulder, CO, USA
- Center for Theory of Quantum Matter, University of Colorado, Boulder, CO, USA
| | - Zhijing Niu
- JILA, NIST, and Department of Physics, University of Colorado, Boulder, CO, USA
| | - Vera M Schäfer
- JILA, NIST, and Department of Physics, University of Colorado, Boulder, CO, USA
- Max-Planck-Institut für Kernphysik, Heidelberg, Germany
| | - Robert J Lewis-Swan
- Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, OK, USA
- Center for Quantum Research and Technology, University of Oklahoma, Norman, OK, USA
| | - Ana Maria Rey
- JILA, NIST, and Department of Physics, University of Colorado, Boulder, CO, USA.
- Center for Theory of Quantum Matter, University of Colorado, Boulder, CO, USA.
| | - James K Thompson
- JILA, NIST, and Department of Physics, University of Colorado, Boulder, CO, USA.
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5
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Sundar B, Barberena D, Orioli AP, Chu A, Thompson JK, Rey AM, Lewis-Swan RJ. Bosonic Pair Production and Squeezing for Optical Phase Measurements in Long-Lived Dipoles Coupled to a Cavity. PHYSICAL REVIEW LETTERS 2023; 130:113202. [PMID: 37001062 DOI: 10.1103/physrevlett.130.113202] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Accepted: 02/14/2023] [Indexed: 06/19/2023]
Abstract
We propose to simulate bosonic pair creation using large arrays of long-lived dipoles with multilevel internal structure coupled to an undriven optical cavity. Entanglement between the atoms, generated by the exchange of virtual photons through a common cavity mode, grows exponentially fast and is described by two-mode squeezing of effective bosonic quadratures. The mapping between an effective bosonic model and the natural spin description of the dipoles allows us to realize the analog of optical homodyne measurements via straightforward global rotations and population measurements of the electronic states, and we propose to exploit this for quantum-enhanced sensing of an optical phase (common and differential between two ensembles). We discuss a specific implementation based on Sr atoms and show that our sensing protocol is robust to sources of decoherence intrinsic to cavity platforms. Our proposal can open unique opportunities for next-generation optical atomic clocks.
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Affiliation(s)
- Bhuvanesh Sundar
- Center for Theory of Quantum Matter, University of Colorado, Boulder, Colorado 80309, USA
- JILA, NIST, Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - Diego Barberena
- Center for Theory of Quantum Matter, University of Colorado, Boulder, Colorado 80309, USA
- JILA, NIST, Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - Asier Piñeiro Orioli
- Center for Theory of Quantum Matter, University of Colorado, Boulder, Colorado 80309, USA
- JILA, NIST, Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - Anjun Chu
- Center for Theory of Quantum Matter, University of Colorado, Boulder, Colorado 80309, USA
- JILA, NIST, Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - James K Thompson
- JILA, NIST, Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - Ana Maria Rey
- Center for Theory of Quantum Matter, University of Colorado, Boulder, Colorado 80309, USA
- JILA, NIST, Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - Robert J Lewis-Swan
- Homer L. Dodge Department of Physics and Astronomy, The University of Oklahoma, Norman, Oklahoma 73019, USA
- Center for Quantum Research and Technology, The University of Oklahoma, Norman, Oklahoma 73019, USA
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6
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He R, Rasmita A, Zhou L, Liang L, Cai X, Chen J, Cai H, Gao W, Liu X. Magnetically Tunable Spontaneous Superradiance from Mesoscopic Perovskite Emitter Clusters. J Phys Chem Lett 2023; 14:2627-2634. [PMID: 36888962 DOI: 10.1021/acs.jpclett.3c00135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Perovskite emitters are promising materials as next-generation optical sources due to their low fabrication cost and high quantum yield. In particular, the superradiant emission from a few coherently coupled perovskite emitters can be used to produce a bright entangled photon source. Here, we report the observation of superradiance from mesoscopic (<55) CsPbBr3 perovskite emitters, which have a much smaller ensemble size than the previously reported results (>106 emitters). The superradiance is spontaneously generated by off-resonance excitation and detected by time-resolved photoluminescence and second-order photon correlation measurements. We observed a remarkable magnetic tunability of the superradiant photon bunching, indicating a magnetic field-induced decoherence process. The experimental results can be well explained using a theoretical framework based on the microscopic master equation. Our findings shed light on the superradiance mechanism in perovskite emitters and enable low-cost quantum light sources based on perovskite.
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Affiliation(s)
- Ruihua He
- Department of Chemistry, National University of Singapore, Singapore 117543, Singapore
| | - Abdullah Rasmita
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological UniversityRINGGOLD, Singapore 637371, Singapore
| | - Lei Zhou
- Department of Chemistry, National University of Singapore, Singapore 117543, Singapore
| | - Liangliang Liang
- Department of Chemistry, National University of Singapore, Singapore 117543, Singapore
| | - Xiangbin Cai
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological UniversityRINGGOLD, Singapore 637371, Singapore
| | - Jiaye Chen
- Department of Chemistry, National University of Singapore, Singapore 117543, Singapore
| | - Hongbing Cai
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological UniversityRINGGOLD, Singapore 637371, Singapore
- The Photonics Institute and Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore 639798, Singapore
| | - Weibo Gao
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological UniversityRINGGOLD, Singapore 637371, Singapore
- The Photonics Institute and Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore 639798, Singapore
- Centre for Quantum Technologies, National University of Singapore, Singapore 117543, Singapore
| | - Xiaogang Liu
- Department of Chemistry, National University of Singapore, Singapore 117543, Singapore
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research, Singapore 138634, Singapore
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7
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On Macroscopic Quantum Coherence with Synchronized Atoms and Molecules: Superradiance. Processes (Basel) 2022. [DOI: 10.3390/pr10091885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The collective behavior of quantum particles is one of the most intriguing phenomena in quantum optics. In particular, superradiance refers to spontaneous collective emissions from a group of quantum particles behaving collectively as a whole due to the buildup of macroscopic quantum coherence. An important question is whether macroscopic quantum coherence is constructed by means of a quantum synchronization (i.e., a quantum analog of classical synchronization) or not. The purpose of this article is to draw attention to this question from the author’s perspective. A few selected studies relevant to synchronized atoms and molecules are discussed. The author concludes that collective behaviors of quantum particles may be formulated as quantum synchronizations, but extensive studies are still needed to confirm this hypothesis.
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8
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Rosa-Medina R, Ferri F, Finger F, Dogra N, Kroeger K, Lin R, Chitra R, Donner T, Esslinger T. Observing Dynamical Currents in a Non-Hermitian Momentum Lattice. PHYSICAL REVIEW LETTERS 2022; 128:143602. [PMID: 35476481 DOI: 10.1103/physrevlett.128.143602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 02/22/2022] [Accepted: 03/03/2022] [Indexed: 06/14/2023]
Abstract
We report on the experimental realization and detection of dynamical currents in a spin-textured lattice in momentum space. Collective tunneling is implemented via cavity-assisted Raman scattering of photons by a spinor Bose-Einstein condensate into an optical cavity. The photon field inducing the tunneling processes is subject to cavity dissipation, resulting in effective directional dynamics in a non-Hermitian setting. We observe that the individual tunneling events are superradiant in nature and locally resolve them in the lattice by performing real-time, frequency-resolved measurements of the leaking cavity field. The results can be extended to a regime exhibiting a cascade of currents and simultaneous coherences between multiple lattice sites, where numerical simulations provide further understanding of the dynamics. Our observations showcase dynamical tunneling in momentum-space lattices and provide prospects to realize dynamical gauge fields in driven-dissipative settings.
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Affiliation(s)
| | - Francesco Ferri
- Institute for Quantum Electronics, ETH Zürich, 8093 Zürich, Switzerland
| | - Fabian Finger
- Institute for Quantum Electronics, ETH Zürich, 8093 Zürich, Switzerland
| | - Nishant Dogra
- Institute for Quantum Electronics, ETH Zürich, 8093 Zürich, Switzerland
| | - Katrin Kroeger
- Institute for Quantum Electronics, ETH Zürich, 8093 Zürich, Switzerland
| | - Rui Lin
- Institute for Theoretical Physics, ETH Zürich, 8093 Zürich, Switzerland
| | - R Chitra
- Institute for Theoretical Physics, ETH Zürich, 8093 Zürich, Switzerland
| | - Tobias Donner
- Institute for Quantum Electronics, ETH Zürich, 8093 Zürich, Switzerland
| | - Tilman Esslinger
- Institute for Quantum Electronics, ETH Zürich, 8093 Zürich, Switzerland
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9
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Glicenstein A, Ferioli G, Browaeys A, Ferrier-Barbut I. From superradiance to subradiance: exploring the many-body Dicke ladder. OPTICS LETTERS 2022; 47:1541-1544. [PMID: 35290359 DOI: 10.1364/ol.451903] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
We report a time-resolved study of collective emission in dense ensembles of two-level atoms. We compare, on the same sample, the buildup of superradiance and subradiance from the ensemble when driven by a strong laser. This allows us to measure the dynamics of the population of superradiant and subradiant states as a function of time. In particular, we demonstrate the buildup in time of subradiant states through superradiant dynamics. This illustrates the dynamics of the many-body density matrix of superradiant ensembles of two-level atoms when departing from the ideal conditions of Dicke superradiance, in which symmetry forbids the population of subradiant states.
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10
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Hotter C, Plankensteiner D, Kazakov G, Ritsch H. Continuous multi-step pumping of the optical clock transition in alkaline-earth atoms with minimal perturbation. OPTICS EXPRESS 2022; 30:5553-5568. [PMID: 35209515 DOI: 10.1364/oe.445976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 01/03/2022] [Indexed: 06/14/2023]
Abstract
A suitable scheme to continuously create inversion on an optical clock transition with negligible perturbation is a key missing ingredient required to build an active optical atomic clock. Repumping of the atoms on the narrow transition typically needs several pump lasers in a multi step process involving several auxiliary levels. In general this creates large effective level shifts and a line broadening, strongly limiting clock accuracy. Here we present an extensive theoretical study for a realistic multi-level implementation in search of parameter regimes where a sufficient inversion can be achieved with minimal perturbations. Fortunately we are able to identify a useful operating regime, where the frequency shifts remain small and controllable, only weakly perturbing the clock transition for useful pumping rates. For practical estimates of the corresponding clock performance, we introduce a straightforward mapping of the multilevel pump scheme to an effective energy shift and broadening of parameters for the reduced two-level laser model system. This allows us to evaluate the resulting laser power and spectrum using well-known methods.
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11
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Zhang Y, Shan C, Mølmer K. Active Frequency Measurement on Superradiant Strontium Clock Transitions. PHYSICAL REVIEW LETTERS 2022; 128:013604. [PMID: 35061453 DOI: 10.1103/physrevlett.128.013604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 12/13/2021] [Indexed: 06/14/2023]
Abstract
We develop a stochastic mean-field theory to describe active frequency measurements of pulsed superradiant emission, studied in a recent experiment with strontium-87 atoms trapped in an optical lattice inside an optical cavity [M. Norcia et al., Phys. Rev. X 8, 021036 (2018)PRXHAE2160-330810.1103/PhysRevX.8.021036]. Our theory reveals the intriguing dynamics of atomic ensembles with multiple transition frequencies, and it reproduces the superradiant beats signal, noisy power spectra, and frequency uncertainty in remarkable agreement with the experiments. Moreover, using longer superradiant pulses of similar strength and shortening the experimental duty cycle, we predict a short-term frequency uncertainty 7×10^{-17}/sqrt[τ/s], which makes active frequency measurements with superradiant transitions comparable with the record performance of current frequency standards [M. Schioppo et al., Nat. Photonics 11, 48 (2017)NPAHBY1749-488510.1038/nphoton.2016.231]. Our theory combines cavity quantum electrodynamics and quantum measurement theory, and it can be readily applied to explore conditional quantum dynamics and describe frequency measurements for other processes such as steady-state superradiance and superradiant Raman lasing.
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Affiliation(s)
- Yuan Zhang
- Henan Key Laboratory of Diamond Optoelectronic Materials and Devices, Key Laboratory of Material Physics Ministry of Education, School of Physics and Microelectronics, Zhengzhou University, Daxue Road 75, Zhengzhou 450052, China
| | - Chongxin Shan
- Henan Key Laboratory of Diamond Optoelectronic Materials and Devices, Key Laboratory of Material Physics Ministry of Education, School of Physics and Microelectronics, Zhengzhou University, Daxue Road 75, Zhengzhou 450052, China
| | - Klaus Mølmer
- Center for Complex Quantum Systems, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark and Aarhus Institute of Advanced Studies, Aarhus University, Høegh-Guldbergs Gade 6B, DK-8000 Aarhus C, Denmark
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12
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Ferioli G, Glicenstein A, Robicheaux F, Sutherland RT, Browaeys A, Ferrier-Barbut I. Laser-Driven Superradiant Ensembles of Two-Level Atoms near Dicke Regime. PHYSICAL REVIEW LETTERS 2021; 127:243602. [PMID: 34951804 DOI: 10.1103/physrevlett.127.243602] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 11/03/2021] [Indexed: 06/14/2023]
Abstract
We report the experimental observation of a superradiant emission emanating from an elongated dense ensemble of laser cooled two-level atoms, with a radial extent smaller than the transition wavelength. In the presence of a strong driving laser, we observe that the system is superradiant along its symmmetry axis. This occurs even though the driving laser is orthogonal to the superradiance direction. This superradiance modifies the spontaneous emission, and, resultantly, the Rabi oscillations. We also investigate Dicke superradiance in the emission of an almost fully inverted system as a function of the atom number. The experimental results are in qualitative agreement with ab-initio, beyond-mean-field calculations.
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Affiliation(s)
- G Ferioli
- Université Paris-Saclay, Institut d'Optique Graduate School, CNRS, Laboratoire Charles Fabry, 91127, Palaiseau, France
| | - A Glicenstein
- Université Paris-Saclay, Institut d'Optique Graduate School, CNRS, Laboratoire Charles Fabry, 91127, Palaiseau, France
| | - F Robicheaux
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA
- Purdue Quantum Science and Engineering Institute, Purdue University, West Lafayette, Indiana 47907, USA
| | - R T Sutherland
- Department of Electrical and Computer Engineering, Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, Texas 78249, USA
| | - A Browaeys
- Université Paris-Saclay, Institut d'Optique Graduate School, CNRS, Laboratoire Charles Fabry, 91127, Palaiseau, France
| | - I Ferrier-Barbut
- Université Paris-Saclay, Institut d'Optique Graduate School, CNRS, Laboratoire Charles Fabry, 91127, Palaiseau, France
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13
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Zyablovsky AA, Andrianov ES, Doronin IV, Lozovik YE, Vinogradov AP. Long-range atomic correlations as a source of coherent light generation. OPTICS LETTERS 2021; 46:5292-5295. [PMID: 34724458 DOI: 10.1364/ol.439582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 10/01/2021] [Indexed: 06/13/2023]
Abstract
In this Letter, we give a new, to the best of our knowledge, perspective on the origin of light coherence in lasers. We demonstrate that a coherence appears below the lasing threshold and manifests itself as long-range correlations between polarizations of active medium atoms. These correlations contribute to the formation of a collective state of atomic polarizations and electromagnetic field modes, which interacts more effectively with the active medium and lases when pumping exceeds the lasing threshold. We demonstrate that inhibiting these atomic correlations leads to the destruction of the collective state and suppression of lasing. The obtained results open up new ways to control coherence.
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14
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Bychek A, Hotter C, Plankensteiner D, Ritsch H. Superradiant lasing in inhomogeneously broadened ensembles with spatially varying coupling. OPEN RESEARCH EUROPE 2021; 1:73. [PMID: 37645148 PMCID: PMC10446144 DOI: 10.12688/openreseurope.13781.2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/17/2021] [Indexed: 08/31/2023]
Abstract
Background: Theoretical studies of superradiant lasing on optical clock transitions predict a superb frequency accuracy and precision closely tied to the bare atomic linewidth. Such a superradiant laser is also robust against cavity fluctuations when the spectral width of the lasing mode is much larger than that of the atomic medium. Recent predictions suggest that this unique feature persists even for a hot and thus strongly broadened ensemble, provided the effective atom number is large enough. Methods: Here we use a second-order cumulant expansion approach to study the power, linewidth and lineshifts of such a superradiant laser as a function of the inhomogeneous width of the ensemble including variations of the spatial atom-field coupling within the resonator. Results: We present conditions on the atom numbers, the pump and coupling strengths required to reach the buildup of collective atomic coherence as well as scaling and limitations for the achievable laser linewidth. Conclusions: We show how sufficiently large numbers of atoms subject to strong optical pumping can induce synchronization of the atomic dipoles over a large bandwidth. This generates collective stimulated emission of light into the cavity mode leading to narrow-band laser emission at the average of the atomic frequency distribution. The linewidth is orders of magnitudes smaller than that of the cavity as well as the inhomogeneous gain broadening and exhibits reduced sensitivity to cavity frequency noise.
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Affiliation(s)
- Anna Bychek
- Institute for Theoretical Physics, University of Innsbruck, Innsbruck, 6020, Austria
| | - Christoph Hotter
- Institute for Theoretical Physics, University of Innsbruck, Innsbruck, 6020, Austria
| | - David Plankensteiner
- Institute for Theoretical Physics, University of Innsbruck, Innsbruck, 6020, Austria
| | - Helmut Ritsch
- Institute for Theoretical Physics, University of Innsbruck, Innsbruck, 6020, Austria
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15
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Jin L. Performance manipulation of the squeezed coherent light source based on four-wave mixing. OPTICS EXPRESS 2021; 29:30198-30207. [PMID: 34614747 DOI: 10.1364/oe.435735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 08/24/2021] [Indexed: 06/13/2023]
Abstract
We present performance manipulation of the squeezed coherent light source based on four-wave mixing (FWM) in alkaline-earth atoms. We investigate the dynamic response of the system and the spectroscopic feature of lasing generated by resonantly enhanced wave-mixing in coherently prepared system. In this method, the spectral purity and stability of the wave-mixing lasing can be manipulated at will by choosing optimal laser parameters. We also analyze the effect of Langevin noise fluctuations on the system and the relative-intensity noise spectrum of the wave-mixing lasing is well below the standard quantum limit (down to -4.7 dB). This work opens new possibilities for alternative routes to laser stabilization and provides a promising path to realize precision metrology.
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16
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Eckner WJ, Young AW, Schine N, Kaufman AM. High-power, fiber-laser-based source for magic-wavelength trapping in neutral-atom optical clocks. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:093001. [PMID: 34598487 DOI: 10.1063/5.0057619] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Accepted: 08/22/2021] [Indexed: 06/13/2023]
Abstract
We present a continuous-wave, 810 nm laser with watt-level powers. Our system is based on difference-frequency generation of 532 and 1550 nm fiber lasers in a single pass through periodically poled lithium niobate. We measure the broadband spectral noise and relative intensity noise to be compatible with off-resonant dipole trapping of ultracold atoms. Given the large bandwidth of the fiber amplifiers, the output can be optimized for a range of wavelengths, including the strontium clock-magic-wavelength of 813 nm. Furthermore, with the exploration of more appropriate nonlinear crystals, we believe that there is a path toward scaling this proof-of-principle design to many watts of power and that this approach could provide a robust, rack-mountable trapping laser for future use in strontium-based optical clocks.
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Affiliation(s)
- William J Eckner
- JILA, University of Colorado and National Institute of Standards and Technology, and Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - Aaron W Young
- JILA, University of Colorado and National Institute of Standards and Technology, and Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - Nathan Schine
- JILA, University of Colorado and National Institute of Standards and Technology, and Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - Adam M Kaufman
- JILA, University of Colorado and National Institute of Standards and Technology, and Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
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17
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Yu D, Vollmer F. Microscale whispering-gallery-mode light sources with lattice-confined atoms. Sci Rep 2021; 11:13899. [PMID: 34230545 PMCID: PMC8260733 DOI: 10.1038/s41598-021-93295-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 06/23/2021] [Indexed: 11/11/2022] Open
Abstract
Microlasers, relying on the strong coupling between active particles and optical microcavity, exhibit fundamental differences from conventional lasers, such as multi-threshold/thresholdless behavior and nonclassical photon emission. As light sources, microlasers possess extensive applications in precision measurement, quantum information processing, and biochemical sensing. Here we propose a whispering-gallery-mode microlaser scheme, where ultracold alkaline-earth metal atoms, i.e., gain medium, are tightly confined in a two-color evanescent lattice that is in the ring shape and formed around a microsphere. To suppress the influence of the lattice-induced ac Stark shift on the moderately-narrow-linewidth laser transition, the red-detuned trapping beams operate at a magic wavelength while the wavelength of the blue-detuned trapping beam is set close to the other magic wavelength. The tiny mode volume and high quality factor of the microsphere ensure the strong atom-microcavity coupling in the bad-cavity regime. As a result, both saturation photon and critical atom numbers, which characterize the laser performance, are substantially reduced below unity. We explore the lasing action of the coupled system by using the Monte Carlo approach. Our scheme may be potentially generalized to the microlasers based on the forbidden clock transitions, holding the prospect for microscale active optical clocks in precision measurement and frequency metrology.
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Affiliation(s)
- Deshui Yu
- Living Systems Institute, Physics and Astronomy, University of Exeter, Exeter, EX4 4QD, UK.
| | - Frank Vollmer
- Living Systems Institute, Physics and Astronomy, University of Exeter, Exeter, EX4 4QD, UK
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18
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Zhang Y, Shan C, Mølmer K. Ultranarrow Superradiant Lasing by Dark Atom-Photon Dressed States. PHYSICAL REVIEW LETTERS 2021; 126:123602. [PMID: 33834832 DOI: 10.1103/physrevlett.126.123602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 12/22/2020] [Accepted: 02/22/2021] [Indexed: 06/12/2023]
Abstract
We show that incoherent pumping of an optical lattice clock system with ultracold strontium-88 atoms produces laser light with a ≃10 Hz linewidth when the atoms are exposed to a magnetic field. This linewidth is orders of magnitude smaller than both the cavity linewidth and the incoherent atomic decay and excitation rates. The narrow lasing is due to an interplay of multiatom superradiant effects and the coupling of bright and dark atom-light dressed states by the magnetic field.
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Affiliation(s)
- Yuan Zhang
- Henan Key Laboratory of Diamond Optoelectronic Materials and Devices, Key Laboratory of Material Physics, Ministry of Education, School of Physics and Microelectronics, Zhengzhou University, Daxue Road 75, 450052 Zhengzhou, China
| | - Chongxin Shan
- Henan Key Laboratory of Diamond Optoelectronic Materials and Devices, Key Laboratory of Material Physics, Ministry of Education, School of Physics and Microelectronics, Zhengzhou University, Daxue Road 75, 450052 Zhengzhou, China
| | - Klaus Mølmer
- Center for Complex Quantum Systems, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark
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19
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Doronin IV, Zyablovsky AA, Andrianov ES, Pukhov AA, Lozovik YE, Vinogradov AP. Universal lasing condition. Sci Rep 2021; 11:4197. [PMID: 33603084 PMCID: PMC7893181 DOI: 10.1038/s41598-021-83701-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Accepted: 02/05/2021] [Indexed: 01/31/2023] Open
Abstract
Usually, the cavity is considered an intrinsic part of laser design to enable coherent emission. For different types of cavities, it is assumed that the light coherence is achieved by different ways. We show that regardless of the type of cavity, the lasing condition is universal and is determined by the ratio of the width of the atomic spectrum to the product of the number of atoms and the spontaneous radiation rate in the laser structure. We demonstrate that cavity does not play a crucial role in lasing since it merely decreases the threshold by increasing the photon emission rate thanks to the Purcell effect. A threshold reduction can be achieved in a cavity-free structure by tuning the local density of states of the electromagnetic field. This paves the way for the design of laser devices based on cavity-free systems.
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Affiliation(s)
- Ilya V Doronin
- Dukhov Research Institute of Automatics (VNIIA), 22 Sushchevskaya, Moscow, 127055, Russia
- Moscow Institute of Physics and Technology, 9 Institutskiy pereulok, Moscow, 141700, Russia
- Institute for Theoretical and Applied Electromagnetics, 13 Izhorskaya, Moscow, 125412, Russia
| | - Alexander A Zyablovsky
- Dukhov Research Institute of Automatics (VNIIA), 22 Sushchevskaya, Moscow, 127055, Russia.
- Moscow Institute of Physics and Technology, 9 Institutskiy pereulok, Moscow, 141700, Russia.
- Institute for Theoretical and Applied Electromagnetics, 13 Izhorskaya, Moscow, 125412, Russia.
| | - Evgeny S Andrianov
- Dukhov Research Institute of Automatics (VNIIA), 22 Sushchevskaya, Moscow, 127055, Russia
- Moscow Institute of Physics and Technology, 9 Institutskiy pereulok, Moscow, 141700, Russia
- Institute for Theoretical and Applied Electromagnetics, 13 Izhorskaya, Moscow, 125412, Russia
| | - Alexander A Pukhov
- Dukhov Research Institute of Automatics (VNIIA), 22 Sushchevskaya, Moscow, 127055, Russia
- Institute for Theoretical and Applied Electromagnetics, 13 Izhorskaya, Moscow, 125412, Russia
| | - Yurii E Lozovik
- Dukhov Research Institute of Automatics (VNIIA), 22 Sushchevskaya, Moscow, 127055, Russia
- Institute of Spectroscopy Russian Academy of Sciences, 5 Fizicheskaya, Troitsk, Moscow, 108840, Russia
| | - Alexey P Vinogradov
- Dukhov Research Institute of Automatics (VNIIA), 22 Sushchevskaya, Moscow, 127055, Russia
- Institute for Theoretical and Applied Electromagnetics, 13 Izhorskaya, Moscow, 125412, Russia
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20
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Liu H, Jäger SB, Yu X, Touzard S, Shankar A, Holland MJ, Nicholson TL. Rugged mHz-Linewidth Superradiant Laser Driven by a Hot Atomic Beam. PHYSICAL REVIEW LETTERS 2020; 125:253602. [PMID: 33416357 DOI: 10.1103/physrevlett.125.253602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 11/19/2020] [Indexed: 06/12/2023]
Abstract
We propose a new type of superradiant laser based on a hot atomic beam traversing an optical cavity. We show that the theoretical minimum linewidth and maximum power are competitive with the best ultracoherent clock lasers. Also, our system operates naturally in continuous wave mode, which has been elusive for superradiant lasers so far. Unlike existing ultracoherent lasers, our design is simple and rugged. This makes it a candidate for the first widely accessible ultracoherent laser, as well as the first to realize sought-after applications of ultracoherent lasers in challenging environments.
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Affiliation(s)
- Haonan Liu
- JILA, National Institute of Standards and Technology, and University of Colorado, Boulder, Colorado 80309-0440, USA
| | - Simon B Jäger
- JILA, National Institute of Standards and Technology, and University of Colorado, Boulder, Colorado 80309-0440, USA
| | - Xianquan Yu
- Centre for Quantum Technologies, Department of Physics, National University of Singapore, Singapore 117543
| | - Steven Touzard
- Centre for Quantum Technologies, Department of Physics, National University of Singapore, Singapore 117543
| | - Athreya Shankar
- JILA, National Institute of Standards and Technology, and University of Colorado, Boulder, Colorado 80309-0440, USA
| | - Murray J Holland
- JILA, National Institute of Standards and Technology, and University of Colorado, Boulder, Colorado 80309-0440, USA
| | - Travis L Nicholson
- Centre for Quantum Technologies, Department of Physics, National University of Singapore, Singapore 117543
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21
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Carollo F, Brandner K, Lesanovsky I. Nonequilibrium Many-Body Quantum Engine Driven by Time-Translation Symmetry Breaking. PHYSICAL REVIEW LETTERS 2020; 125:240602. [PMID: 33412035 DOI: 10.1103/physrevlett.125.240602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 11/03/2020] [Indexed: 06/12/2023]
Abstract
Quantum many-body systems out of equilibrium can host intriguing phenomena such as transitions to exotic dynamical states. Although this emergent behaviour can be observed in experiments, its potential for technological applications is largely unexplored. Here, we investigate the impact of collective effects on quantum engines that extract mechanical work from a many-body system. Using an optomechanical cavity setup with an interacting atomic gas as a working fluid, we demonstrate theoretically that such engines produce work under periodic driving. The stationary cycle of the working fluid features nonequilibrium phase transitions, resulting in abrupt changes of the work output. Remarkably, we find that our many-body quantum engine operates even without periodic driving. This phenomenon occurs when its working fluid enters a phase that breaks continuous time-translation symmetry: The emergent time-crystalline phase can sustain the motion of a load generating mechanical work. Our findings pave the way for designing novel nonequilibrium quantum machines.
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Affiliation(s)
- Federico Carollo
- Institut für Theoretische Physik, Universität Tübingen, Auf der Morgenstelle 14, 72076 Tübingen, Germany
| | - Kay Brandner
- School of Physics and Astronomy and Centre for the Mathematics and Theoretical Physics of Quantum Non-Equilibrium Systems, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Igor Lesanovsky
- Institut für Theoretische Physik, Universität Tübingen, Auf der Morgenstelle 14, 72076 Tübingen, Germany
- School of Physics and Astronomy and Centre for the Mathematics and Theoretical Physics of Quantum Non-Equilibrium Systems, University of Nottingham, Nottingham NG7 2RD, United Kingdom
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22
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Abstract
Active clocks could provide better stabilities during initial stages of measurements over passive clocks, in which stabilities become saturated only after long-term measurements. This unique feature of an active clock has led to search for suitable candidates to construct such clocks. The other challenging task of an atomic clock is to reduce its possible systematics. A major part of the optical lattice atomic clocks based on neutral atoms are reduced by trapping atoms at the magic wavelengths of the optical lattice lasers. Keeping this in mind, we find the magic wavelengths between all possible hyperfine levels of the transitions in Rb and Cs atoms that were earlier considered to be suitable for making optical active clocks. To validate the results, we give the static dipole polarizabilities of Rb and Cs atoms using the electric dipole transition amplitudes that are used to evaluate the dynamic dipole polarizabilities and compare them with the available literature values.
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23
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Harvie G, Butcher A, Goldwin J. Coherence time of a cold-atom laser below threshold. OPTICS LETTERS 2020; 45:5448-5451. [PMID: 33001916 DOI: 10.1364/ol.402975] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 08/28/2020] [Indexed: 06/11/2023]
Abstract
We experimentally study the coherence time of a below-threshold Raman laser in which the gain medium is a gas of magneto-optically trapped atoms. The second-order optical coherence exhibits photon bunching with a correlation time that is varied by two orders of magnitude by controlling the gain. Results are in good agreement with a simple analytic model that suggests the effect is dominated by gain, rather than dispersion, in this system. Cavity ring-down measurements show the photon lifetime, related to the first-order coherence time, is also increased.
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24
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An H, Jeong Y. Numerical study of superradiant mixing by an unsynchronized superradiant state of multiple atomic ensembles. OPTICS EXPRESS 2020; 28:22276-22286. [PMID: 32752493 DOI: 10.1364/oe.393311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 06/22/2020] [Indexed: 06/11/2023]
Abstract
We numerically analyze superradiant dynamics in atomic ensembles that have different transition frequencies using a numerical model that can take account of the transient behavior of an unsynchronized superradiant state. The numerical results unveil that the superradiant emission of a periodic pulse train can be induced by means of collective multiple frequency generation, which we call superradiant mixing. This is, in fact, due to the superradiant coupling of unsynchronized atomic ensembles. We numerically investigate the superradiant mixing in detail, varying the collective decay rate, repumping rate, and the number of the individual atomic ensembles with detuned frequencies. This work broadens our understanding of the collective atomic behavior in a detuned system, and it also suggests a novel method for frequency generation without relying on the conventional Kerr nonlinear effect.
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25
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Exploring dynamical phase transitions with cold atoms in an optical cavity. Nature 2020; 580:602-607. [DOI: 10.1038/s41586-020-2224-x] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 02/10/2020] [Indexed: 11/09/2022]
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26
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Gogyan A, Kazakov G, Bober M, Zawada M. Characterisation and feasibility study for superradiant lasing in 40Ca atoms. OPTICS EXPRESS 2020; 28:6881-6892. [PMID: 32225926 DOI: 10.1364/oe.381991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 02/08/2020] [Indexed: 06/10/2023]
Abstract
Superradiant active clocks operating on narrow linewidth clock transitions are predicted to achieve precision orders of magnitude higher than any currently existing optical atomic clocks. We introduce a theory of superradiant lasing and implement it for the example of 40Ca atoms. The presented model, however, is valid for any two- or three-level system in an optical lattice. We perform a feasibility analysis and suggest a set of parameters for the experimental fulfillment of superradiant lasing in Ca. Moreover, we present an overview of different magic wavelengths for the 4s2 1S0 ↔ 4s4p3P1 (mJ = 0) transition in Ca for different polarizations and a robustness analysis of these magic conditions. We also report the magic-zero wavelengths for the 4s4p3P1, mJ = 0 state.
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27
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Hotter C, Plankensteiner D, Ostermann L, Ritsch H. Superradiant cooling, trapping, and lasing of dipole-interacting clock atoms. OPTICS EXPRESS 2019; 27:31193-31206. [PMID: 31684354 DOI: 10.1364/oe.27.031193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 08/22/2019] [Indexed: 06/10/2023]
Abstract
A cold atomic gas with an inverted population on a transition coupled to a field mode of an optical resonator constitutes a generic model of a laser. For quasi-continuous operation, external pumping, trapping and cooling of the atoms is required to confine them in order to achieve enough gain inside the resonator. As inverted atoms are high-field seekers in blue detuned light fields, tuning the cavity mode to the blue side of the atomic gain transition allows for combining lasing with stimulated cavity cooling and dipole trapping of the atoms at the antinodes of the laser field. We study such a configuration using a semiclassical description of particle motion along the cavity axis. In extension of earlier work we include free space atomic and cavity decay as well as atomic dipole-dipole interactions and their corresponding forces. We show that for a proper choice of parameters even in the bad cavity limit the atoms can create a sufficiently strong field inside the resonator such that they are trapped and cooled via the superradiant lasing action with less than one photon on average inside the cavity.
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28
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Laske T, Winter H, Hemmerich A. Pulse Delay Time Statistics in a Superradiant Laser with Calcium Atoms. PHYSICAL REVIEW LETTERS 2019; 123:103601. [PMID: 31573286 DOI: 10.1103/physrevlett.123.103601] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2019] [Indexed: 06/10/2023]
Abstract
Cold samples of calcium atoms are prepared in the metastable ^{3}P_{1} state inside an optical cavity resonant with the narrow band (375 Hz) ^{1}S_{0}→^{3}P_{1} intercombination line at 657 nm. We observe a superradiant emission of hyperbolic secant shaped pulses into the cavity with an intensity proportional to the square of the atom number, a duration much shorter than the natural lifetime of the ^{3}P_{1} state, and a delay time fluctuating from shot to shot in excellent agreement with theoretical predictions. Our incoherent pumping scheme to produce inversion on the ^{1}S_{0}→^{3}P_{1} transition should be extendable to allow for continuous wave laser operation.
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Affiliation(s)
- Torben Laske
- Institut für Laser-Physik and Zentrum für Optische Quantentechnologien, Universität Hamburg, D-22761 Hamburg, Germany
| | - Hannes Winter
- Institut für Laser-Physik and Zentrum für Optische Quantentechnologien, Universität Hamburg, D-22761 Hamburg, Germany
| | - Andreas Hemmerich
- Institut für Laser-Physik and Zentrum für Optische Quantentechnologien, Universität Hamburg, D-22761 Hamburg, Germany
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29
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Yoon T, Ding Z, Flannery J, Rajabi F, Bajcsy M. Monitoring Raman emission through state population in cold atoms confined inside a hollow-core fiber. OPTICS EXPRESS 2019; 27:17592-17600. [PMID: 31252716 DOI: 10.1364/oe.27.017592] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 05/24/2019] [Indexed: 06/09/2023]
Abstract
We study the spontaneous Raman emission in an ensemble of laser-cooled three-level Λ-type atoms confined inside a hollow-core photonic-bandgap fiber using a novel approach to observe the process. Instead of detecting the emitted light, we measure the number of atoms in the ground state as a function of Raman pump time, which eliminates the need to suppress the pump photons with a high-resolution filter. We describe how this measurement can be used to detect superradiant emission from the atomic ensembles and estimate the number of atoms required to observe Raman superradiance in atomic clouds inside a hollow-core fiber.
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30
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Megyeri B, Harvie G, Lampis A, Goldwin J. Directional Bistability and Nonreciprocal Lasing with Cold Atoms in a Ring Cavity. PHYSICAL REVIEW LETTERS 2018; 121:163603. [PMID: 30387648 DOI: 10.1103/physrevlett.121.163603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Indexed: 06/08/2023]
Abstract
We demonstrate lasing into counterpropagating modes of a ring cavity using a gas of cold atoms as a gain medium. The laser operates under the usual conditions of magneto-optical trapping with no additional fields. We characterize the threshold behavior of the laser and measure the second-order optical coherence. The laser emission exhibits directional bistability, switching randomly between clockwise and counterclockwise modes, and a tunable nonreciprocity is observed as the atoms are displaced along the cavity axis.
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Affiliation(s)
- B Megyeri
- School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - G Harvie
- School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - A Lampis
- School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - J Goldwin
- School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
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31
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Pan D, Shi T, Chen J. Dual-Wavelength Good-Bad-Cavity Laser System for Cavity-Stabilized Active Optical Clock. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2018; 65:1958-1964. [PMID: 30004873 DOI: 10.1109/tuffc.2018.2854738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Active optical clocks (AOCs) have the intrinsic suppression of the influence of the cavity's noise on the output frequency, giving rise to the potentially ultranarrow linewidth. To break the cavity's thermal noise limitation by taking full advantage of the AOC's principle, as well as to achieve a long-term instability, we propose a scheme of cavity-stabilized active optical clock. The system consists of two key procedures. The dual-wavelength (DW) output signals share the same cavity and work in the good- and the bad-cavity regime, respectively. Then, the good-cavity signal is locked to a reference cavity by the Pound-Drever-Hall (PDH) technique to stabilize the main-cavity length. By doing this, the main-cavity's noise is expected to be reduced to the thermal noise floor of the reference cavity. Hence, the frequency stability of the bad-cavity signal will break this noise floor due to the suppression of the cavity-pulling effect. Experimentally, we realize the DW good-bad-cavity laser system by taking the Nd:YAG 1064 nm and Cs 1470 nm transitions as the good- and bad-cavity gain medium. The power and linewidth characteristics of the DW output are studied. Limitation factors of the clock frequency as well as the feasibility of the PDH cavity stabilization are analyzed.
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32
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Bosch Aguilera M, Bouganne R, Dareau A, Scholl M, Beaufils Q, Beugnon J, Gerbier F. Non-linear relaxation of interacting bosons coherently driven on a narrow optical transition. ACTA ACUST UNITED AC 2018. [DOI: 10.1209/0295-5075/123/40004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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33
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Norcia MA, Lewis-Swan RJ, Cline JRK, Zhu B, Rey AM, Thompson JK. Cavity-mediated collective spin-exchange interactions in a strontium superradiant laser. Science 2018; 361:259-262. [DOI: 10.1126/science.aar3102] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 05/25/2018] [Indexed: 11/02/2022]
Affiliation(s)
- Matthew A. Norcia
- JILA, NIST, and Department of Physics, University of Colorado, 440 UCB, Boulder, CO 80309, USA
| | - Robert J. Lewis-Swan
- JILA, NIST, and Department of Physics, University of Colorado, 440 UCB, Boulder, CO 80309, USA
- Center for Theory of Quantum Matter, University of Colorado, Boulder, CO 80309, USA
| | - Julia R. K. Cline
- JILA, NIST, and Department of Physics, University of Colorado, 440 UCB, Boulder, CO 80309, USA
| | - Bihui Zhu
- JILA, NIST, and Department of Physics, University of Colorado, 440 UCB, Boulder, CO 80309, USA
- ITAMP, Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, USA
| | - Ana M. Rey
- JILA, NIST, and Department of Physics, University of Colorado, 440 UCB, Boulder, CO 80309, USA
- Center for Theory of Quantum Matter, University of Colorado, Boulder, CO 80309, USA
| | - James K. Thompson
- JILA, NIST, and Department of Physics, University of Colorado, 440 UCB, Boulder, CO 80309, USA
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34
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Jin L, Jiang Y, Yao Y, Yu H, Bi Z, Ma L. Laser frequency instability of 2 × 10 -16 by stabilizing to 30-cm-long Fabry-Pérot cavities at 578 nm. OPTICS EXPRESS 2018; 26:18699-18707. [PMID: 30114043 DOI: 10.1364/oe.26.018699] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 06/11/2018] [Indexed: 06/08/2023]
Abstract
Laser light at 578 nm is frequency-stabilized to two independent 30-cm-long Fabry-Pérot cavities. To achieve a thermal-noise-limited cavity length stability, the geometry and support configuration of the Fabry-Pérot cavities are optimized. The fractional frequency instability of each cavity-stabilized laser system is 2 × 10-16 at 1 s averaging time, approaching to the thermal-noise-induced length instability of the reference cavity. The most probable linewidth of each laser system is about 0.2 Hz, and the laser frequency noise at Fourier frequency of 1 Hz is 0.1 Hz/√Hz.
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35
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Kim J, Yang D, Oh SH, An K. Coherent single-atom superradiance. Science 2018; 359:662-666. [DOI: 10.1126/science.aar2179] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Accepted: 12/07/2017] [Indexed: 11/02/2022]
Affiliation(s)
- Junki Kim
- Department of Physics and Astronomy and Institute of Applied Physics, Seoul National University, Seoul 08826, Republic of Korea
| | - Daeho Yang
- Department of Physics and Astronomy and Institute of Applied Physics, Seoul National University, Seoul 08826, Republic of Korea
| | - Seung-hoon Oh
- Department of Physics and Astronomy and Institute of Applied Physics, Seoul National University, Seoul 08826, Republic of Korea
| | - Kyungwon An
- Department of Physics and Astronomy and Institute of Applied Physics, Seoul National University, Seoul 08826, Republic of Korea
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Bennetts S, Chen CC, Pasquiou B, Schreck F. Steady-State Magneto-Optical Trap with 100-Fold Improved Phase-Space Density. PHYSICAL REVIEW LETTERS 2017; 119:223202. [PMID: 29286768 DOI: 10.1103/physrevlett.119.223202] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Indexed: 06/07/2023]
Abstract
We demonstrate a continuously loaded ^{88}Sr magneto-optical trap (MOT) with a steady-state phase-space density of 1.3(2)×10^{-3}. This is 2 orders of magnitude higher than reported in previous steady-state MOTs. Our approach is to flow atoms through a series of spatially separated laser cooling stages before capturing them in a MOT operated on the 7.4-kHz linewidth Sr intercombination line using a hybrid slower+MOT configuration. We also demonstrate producing a Bose-Einstein condensate at the MOT location, despite the presence of laser cooling light on resonance with the 30-MHz linewidth transition used to initially slow atoms in a separate chamber. Our steady-state high phase-space density MOT is an excellent starting point for a continuous atom laser and dead-time free atom interferometers or clocks.
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Affiliation(s)
- Shayne Bennetts
- Van der Waals-Zeeman Institute, Institute of Physics, University of Amsterdam, Science Park 904, 1098XH Amsterdam, The Netherlands
| | - Chun-Chia Chen
- Van der Waals-Zeeman Institute, Institute of Physics, University of Amsterdam, Science Park 904, 1098XH Amsterdam, The Netherlands
| | - Benjamin Pasquiou
- Van der Waals-Zeeman Institute, Institute of Physics, University of Amsterdam, Science Park 904, 1098XH Amsterdam, The Netherlands
| | - Florian Schreck
- Van der Waals-Zeeman Institute, Institute of Physics, University of Amsterdam, Science Park 904, 1098XH Amsterdam, The Netherlands
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Winchester MN, Norcia MA, Cline JRK, Thompson JK. Magnetically Induced Optical Transparency on a Forbidden Transition in Strontium for Cavity-Enhanced Spectroscopy. PHYSICAL REVIEW LETTERS 2017; 118:263601. [PMID: 28707949 DOI: 10.1103/physrevlett.118.263601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Indexed: 06/07/2023]
Abstract
In this Letter we realize a narrow spectroscopic feature using a technique that we refer to as magnetically induced optical transparency. A cold ensemble of ^{88}Sr atoms interacts with a single mode of a high-finesse optical cavity via the 7.5 kHz linewidth, spin forbidden ^{1}S_{0} to ^{3}P_{1} transition. By applying a magnetic field that shifts two excited state Zeeman levels, we open a transmission window through the cavity where the collective vacuum Rabi splitting due to a single level would create destructive interference for probe transmission. The spectroscopic feature approaches the atomic transition linewidth, which is much narrower than the cavity linewidth, and is highly immune to the reference cavity length fluctuations that limit current state-of-the-art laser frequency stability.
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Affiliation(s)
- Matthew N Winchester
- JILA, NIST, and Department of Physics, University of Colorado, 440 UCB, Boulder, Colorado 80309, USA
| | - Matthew A Norcia
- JILA, NIST, and Department of Physics, University of Colorado, 440 UCB, Boulder, Colorado 80309, USA
| | - Julia R K Cline
- JILA, NIST, and Department of Physics, University of Colorado, 440 UCB, Boulder, Colorado 80309, USA
| | - James K Thompson
- JILA, NIST, and Department of Physics, University of Colorado, 440 UCB, Boulder, Colorado 80309, USA
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Manzoni MT, Mathey L, Chang DE. Designing exotic many-body states of atomic spin and motion in photonic crystals. Nat Commun 2017; 8:14696. [PMID: 28272466 PMCID: PMC5344972 DOI: 10.1038/ncomms14696] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 01/24/2017] [Indexed: 11/15/2022] Open
Abstract
Cold atoms coupled to photonic crystals constitute an exciting platform for exploring quantum many-body physics. For example, such systems offer the potential to realize strong photon-mediated forces between atoms, which depend on the atomic internal (spin) states, and where both the motional and spin degrees of freedom can exhibit long coherence times. An intriguing question then is whether exotic phases could arise, wherein crystalline or other spatial patterns and spin correlations are fundamentally tied together, an effect that is atypical in condensed matter systems. Here, we analyse one realistic model Hamiltonian in detail. We show that this previously unexplored system exhibits a rich phase diagram of emergent orders, including spatially dimerized spin-entangled pairs, a fluid of composite particles comprised of joint spin-phonon excitations, phonon-induced Néel ordering, and a fractional magnetization plateau associated with trimer formation.
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Affiliation(s)
- Marco T. Manzoni
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
| | - Ludwig Mathey
- Zentrum für Optische Quantentechnologien and Institut für Laserphysik, Universität Hamburg, 22761 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, Hamburg 22761, Germany
| | - Darrick E. Chang
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
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