1
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Zhang YX. Zeno Regime of Collective Emission: Non-Markovianity beyond Retardation. PHYSICAL REVIEW LETTERS 2023; 131:193603. [PMID: 38000421 DOI: 10.1103/physrevlett.131.193603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 08/16/2023] [Accepted: 10/18/2023] [Indexed: 11/26/2023]
Abstract
To build up a collective emission, the atoms in an ensemble must coordinate their behavior by exchanging virtual photons. We study this non-Markovian process in a subwavelength atom chain coupled to a one-dimensional (1D) waveguide and find that retardation is not the only cause of non-Markovianity. The other factor is the memory of the photonic environment, for which a single excited atom needs a finite time, the Zeno regime, to transition from quadratic decay to exponential decay. In the waveguide setup, this crossover has a time scale longer than the retardation, thus impacting the development of collective behavior. By comparing a full quantum treatment with an approach incorporating only the retardation effect, we find that the field memory effect, characterized by the population of atomic excitation, is much more pronounced in collective emissions than that in the decay of a single atom. Our results maybe useful for the dissipation engineering of quantum information processings based on compact atom arrays.
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Affiliation(s)
- Yu-Xiang Zhang
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China; and Hefei National Laboratory, Hefei 230088, China
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2
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Fernández-Fernández D, González-Tudela A. Tunable Directional Emission and Collective Dissipation with Quantum Metasurfaces. PHYSICAL REVIEW LETTERS 2022; 128:113601. [PMID: 35363033 DOI: 10.1103/physrevlett.128.113601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 01/26/2022] [Indexed: 06/14/2023]
Abstract
Subwavelength atomic arrays, recently labeled as quantum metamaterials, have emerged as an exciting platform for obtaining novel quantum optical phenomena. The strong interference effects in these systems generate subradiant excitations that propagate through the atomic array with very long lifetimes. Here, we demonstrate that one can harness these excitations to obtain tunable directional emission patterns and collective dissipative couplings when placing judiciously additional atoms nearby the atomic array. For doing that, we first characterize the optimal square array geometry to obtain directional emission patterns. Then, we characterize the best atomic positions to couple efficiently to the subradiant metasurface excitations and provide several improvement strategies based on entangled atomic clusters or bilayers. Afterward, we also show how the directionality of the emission pattern can be controlled through the relative dipole orientation between the auxiliary atoms and the one of the array. Finally, we benchmark how these directional emission patterns translate into to collective, anisotropic dissipative couplings between the auxiliary atoms by studying the lifetime modification of atomic entangled states.
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Affiliation(s)
- D Fernández-Fernández
- Institute of Fundamental Physics IFF-CSIC, Calle Serrano 113b, 28006 Madrid, Spain
- Instituto de Ciencia de Materiales de Madrid ICMM-CSIC, 28049 Madrid, Spain
| | - A González-Tudela
- Institute of Fundamental Physics IFF-CSIC, Calle Serrano 113b, 28006 Madrid, Spain
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3
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Zhang YX, Mølmer K. Free-Fermion Multiply Excited Eigenstates and Their Experimental Signatures in 1D Arrays of Two-Level Atoms. PHYSICAL REVIEW LETTERS 2022; 128:093602. [PMID: 35302803 DOI: 10.1103/physrevlett.128.093602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 02/17/2022] [Indexed: 06/14/2023]
Abstract
One-dimensional (1D) subwavelength atom arrays display multiply excited subradiant eigenstates which are reminiscent of free fermions. So far, these states have been associated with subradiant states with decay rates ∝N^{-3}, with N the number of atoms, which fundamentally prevents detection of their fermionic features by optical means. In this Letter, we show that free-fermion states generally appear whenever the band of singly excited states has a quadratic dispersion relation at the band edge and, hence, may also be obtained with radiant and even superradiant states. 1D arrays have free-fermion multiply excited eigenstates that are typically either subradiant or (super)radiant, and we show that a simple transformation acts between the two families. Based on this correspondence, we propose different means for their preparation and analyze their experimental signature in optical detection.
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Affiliation(s)
- Yu-Xiang Zhang
- The Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, 2100 Copenhagen Ø, Denmark
| | - Klaus Mølmer
- Aarhus Institute of Advanced Studies, Aarhus University and Center for Complex Quantum Systems (CCQ), Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark
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4
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Ballantine KE, Ruostekoski J. Optical Magnetism and Huygens' Surfaces in Arrays of Atoms Induced by Cooperative Responses. PHYSICAL REVIEW LETTERS 2020; 125:143604. [PMID: 33064535 DOI: 10.1103/physrevlett.125.143604] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 08/31/2020] [Indexed: 06/11/2023]
Abstract
By utilizing strong optical resonant interactions in arrays of atoms with electric dipole transitions, we show how to synthesize collective optical responses that correspond to those formed by arrays of magnetic dipoles and other multipoles. Optically active magnetism with the strength comparable with that of electric dipole transitions is achieved in collective excitation eigenmodes of the array. By controlling the atomic level shifts, an array of spectrally overlapping, crossed electric and magnetic dipoles can be excited, providing a physical realization of a nearly reflectionless quantum Huygens' surface with the full 2π phase control of the transmitted light that allows for extreme wavefront engineering even at a single photon level. We illustrate this by creating a superposition of two different orbital angular momentum states of light from an ordinary input state that has no orbital angular momentum.
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Affiliation(s)
- K E Ballantine
- Department of Physics, Lancaster University, Lancaster LA1 4YB, United Kingdom
| | - J Ruostekoski
- Department of Physics, Lancaster University, Lancaster LA1 4YB, United Kingdom
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5
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Ballantine KE, Ruostekoski J. Radiative Toroidal Dipole and Anapole Excitations in Collectively Responding Arrays of Atoms. PHYSICAL REVIEW LETTERS 2020; 125:063201. [PMID: 32845681 DOI: 10.1103/physrevlett.125.063201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 07/17/2020] [Indexed: 06/11/2023]
Abstract
A toroidal dipole represents an often overlooked electromagnetic excitation distinct from the standard electric and magnetic multipole expansion. We show how a simple arrangement of strongly radiatively coupled atoms can be used to synthesize a toroidal dipole where the toroidal topology is generated by radiative transitions forming an effective poloidal electric current wound around a torus. We extend the protocol for methods to prepare a delocalized collective excitation mode consisting of a synthetic lattice of such toroidal dipoles and a nonradiating, yet oscillating charge-current configuration, dynamic anapole, for which the far-field radiation of a toroidal dipole is identically canceled by an electric dipole.
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Affiliation(s)
- K E Ballantine
- Department of Physics, Lancaster University, Lancaster LA1 4YB, United Kingdom
| | - J Ruostekoski
- Department of Physics, Lancaster University, Lancaster LA1 4YB, United Kingdom
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6
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Piñeiro Orioli A, Rey AM. Dark States of Multilevel Fermionic Atoms in Doubly Filled Optical Lattices. PHYSICAL REVIEW LETTERS 2019; 123:223601. [PMID: 31868417 DOI: 10.1103/physrevlett.123.223601] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Indexed: 06/10/2023]
Abstract
We propose to use fermionic atoms with degenerate ground and excited internal levels (F_{g}→F_{e}), loaded into the motional ground state of an optical lattice with two atoms per lattice site, to realize dark states with no radiative decay. The physical mechanism behind the dark states is an interplay of Pauli blocking and multilevel dipolar interactions. The dark states are independent of lattice geometry, can support an extensive number of excitations, and can be coherently prepared using a Raman scheme taking advantage of the quantum Zeno effect. These attributes make them appealing for atomic clocks, quantum memories, and quantum information on decoherence free subspaces.
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Affiliation(s)
- A 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
| | - A M 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
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7
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Zhang YX, Mølmer K. Theory of Subradiant States of a One-Dimensional Two-Level Atom Chain. PHYSICAL REVIEW LETTERS 2019; 122:203605. [PMID: 31172781 DOI: 10.1103/physrevlett.122.203605] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Indexed: 06/09/2023]
Abstract
Recently, the subradiant states of one-dimensional two-level atom chains coupled to light modes were found to have decay rates obeying a universal scaling, and an unexpected fermionic character of the multiply excited subradiant states was discovered. In this Letter, we theoretically obtain the singly excited subradiant states, and by eliminating the superradiant modes, we demonstrate a relation between the multiply excited subradiant states and the Tonks-Girardeau limit of the Lieb-Liniger model which explains the fermionic behavior. In addition, we identify a new family of subradiant states with correlations different from the fermionic ansatz.
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Affiliation(s)
- Yu-Xiang Zhang
- Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark
| | - Klaus Mølmer
- Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark
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8
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Rotondo P, Sellerio AL, Glorioso P, Caracciolo S, Cosentino Lagomarsino M, Gherardi M. Current quantization and fractal hierarchy in a driven repulsive lattice gas. Phys Rev E 2017; 96:052141. [PMID: 29347707 DOI: 10.1103/physreve.96.052141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Indexed: 06/07/2023]
Abstract
Driven lattice gases are widely regarded as the paradigm of collective phenomena out of equilibrium. While such models are usually studied with nearest-neighbor interactions, many empirical driven systems are dominated by slowly decaying interactions such as dipole-dipole and Van der Waals forces. Motivated by this gap, we study the nonequilibrium stationary state of a driven lattice gas with slow-decayed repulsive interactions at zero temperature. By numerical and analytical calculations of the particle current as a function of the density and of the driving field, we identify (i) an abrupt breakdown transition between insulating and conducting states, (ii) current quantization into discrete phases where a finite current flows with infinite differential resistivity, and (iii) a fractal hierarchy of excitations, related to the Farey sequences of number theory. We argue that the origin of these effects is the competition between scales, which also causes the counterintuitive phenomenon that crystalline states can melt by increasing the density.
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Affiliation(s)
- Pietro Rotondo
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
- Centre for the Mathematics and Theoretical Physics of Quantum Non-equilibrium Systems, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | | | - Pietro Glorioso
- Dipartimento di Fisica, Università degli Studi di Milano, via Celoria 16, 20133 Milano, Italy
| | - Sergio Caracciolo
- Dipartimento di Fisica, Università degli Studi di Milano, via Celoria 16, 20133 Milano, Italy
- INFN Milano, via Celoria 16, 20133 Milano, Italy
| | - Marco Cosentino Lagomarsino
- Sorbonne Universités, UPMC Univ Paris 06, UMR 7238, Computational and Quantitative Biology, 5 Place Jussieu, 75005 Paris, France
- CNRS, UMR 7238, Computational and Quantitative Biology, France
| | - Marco Gherardi
- Dipartimento di Fisica, Università degli Studi di Milano, via Celoria 16, 20133 Milano, Italy
- Sorbonne Universités, UPMC Univ Paris 06, UMR 7238, Computational and Quantitative Biology, 5 Place Jussieu, 75005 Paris, France
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9
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Wang BX, Zhao CY, Kan YH, Huang TC. Design of metasurface polarizers based on two-dimensional cold atomic arrays. OPTICS EXPRESS 2017; 25:18760-18773. [PMID: 29041070 DOI: 10.1364/oe.25.018760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 07/21/2017] [Indexed: 06/07/2023]
Abstract
Engineering light-matter interaction using cold atomic arrays is one of the central topics in modern optics. Here we have demonstrated the capability of two-dimensional asymmetric cold atomic arrays as microscopic metasurfaces for controlling polarization states of light. The designed linear polarizer can lead to an extinction ratio over 20dB as well as a high transmittance over 0.8 for the permitted polarization at zero detuning. For detuned driving light, changing lattice constants can also achieve high performance linear polarizers. We have also accomplished a circular polarizer by manipulating the phases of transmitted light. A theoretical analysis based on Bloch theorem shows the underlying mechanism for this performance is actually attributed to cooperative effects in periodic lattices. Finally, we discuss in detail the effects of system size, lattice imperfection and nonzero driving light linewidth in practical implementation. The present study paves a way to design extremely miniaturized metasurfaces using cold atoms and other two-level systems, showing great potential in quantum information and quantum metrology sciences as well as the fundamental physics of light-matter interaction.
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10
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Perczel J, Borregaard J, Chang DE, Pichler H, Yelin SF, Zoller P, Lukin MD. Topological Quantum Optics in Two-Dimensional Atomic Arrays. PHYSICAL REVIEW LETTERS 2017; 119:023603. [PMID: 28753358 DOI: 10.1103/physrevlett.119.023603] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Indexed: 06/07/2023]
Abstract
We demonstrate that two-dimensional atomic emitter arrays with subwavelength spacing constitute topologically protected quantum optical systems where the photon propagation is robust against large imperfections while losses associated with free space emission are strongly suppressed. Breaking time-reversal symmetry with a magnetic field results in gapped photonic bands with nontrivial Chern numbers and topologically protected, long-lived edge states. Due to the inherent nonlinearity of constituent emitters, such systems provide a platform for exploring quantum optical analogs of interacting topological systems.
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Affiliation(s)
- J Perczel
- Physics Department, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
- Physics Department, Harvard University, Cambridge, Massachusetts 02138, USA
| | - J Borregaard
- Physics Department, Harvard University, Cambridge, Massachusetts 02138, USA
| | - D E Chang
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - H Pichler
- Physics Department, Harvard University, Cambridge, Massachusetts 02138, USA
- ITAMP, Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, USA
| | - S F Yelin
- Physics Department, Harvard University, Cambridge, Massachusetts 02138, USA
- Department of Physics, University of Connecticut, Storrs, Connecticut 06269, USA
| | - P Zoller
- Institute for Theoretical Physics, University of Innsbruck, A-6020 Innsbruck, Austria
- Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, A-6020 Innsbruck, Austria
| | - M D Lukin
- Physics Department, Harvard University, Cambridge, Massachusetts 02138, USA
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11
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Cao L, Mistakidis SI, Deng X, Schmelcher P. Collective excitations of dipolar gases based on local tunneling in superlattices. Chem Phys 2017. [DOI: 10.1016/j.chemphys.2016.08.026] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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12
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Syzranov SV, Wall ML, Zhu B, Gurarie V, Rey AM. Emergent Weyl excitations in systems of polar particles. Nat Commun 2016; 7:13543. [PMID: 27941753 PMCID: PMC5159878 DOI: 10.1038/ncomms13543] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 10/13/2016] [Indexed: 11/23/2022] Open
Abstract
Weyl fermions are massless chiral particles first predicted in 1929 and once thought to describe neutrinos. Although never observed as elementary particles, quasiparticles with Weyl dispersion have recently been experimentally discovered in solid-state systems causing a furore in the research community. Systems with Weyl excitations can display a plethora of fascinating phenomena and offer great potential for improved quantum technologies. Here, we show that Weyl excitations generically exist in three-dimensional systems of dipolar particles with weakly broken time-reversal symmetry (by for example a magnetic field). They emerge as a result of dipolar-interaction-induced transfer of angular momentum between the J=0 and J=1 internal particle levels. We also discuss momentum-resolved Ramsey spectroscopy methods for observing Weyl quasiparticles in cold alkaline-earth-atom systems. Our results provide a pathway for a feasible experimental realization of Weyl quasiparticles and related phenomena in clean and controllable atomic systems.
Systems with Weyl excitations can display very interesting physical phenomena. Here the authors demonstrate that Weyl excitations exist generically in 3D systems of dipolar particles following angular momentum transfer, and discuss how to observe them in cold alkaline-earth-atom systems.
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Affiliation(s)
- Sergey V Syzranov
- Physics Department, University of Colorado, Boulder, Colorado 80309, USA.,JILA, NIST, University of Colorado, Boulder, Colorado 80309, USA.,Center for Theory of Quantum Matter, University of Colorado, Boulder, Colorado 80309, USA.,Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, USA
| | - Michael L Wall
- JILA, NIST, University of Colorado, Boulder, Colorado 80309, USA.,Center for Theory of Quantum Matter, University of Colorado, Boulder, Colorado 80309, USA
| | - Bihui Zhu
- Physics Department, University of Colorado, Boulder, Colorado 80309, USA.,JILA, NIST, University of Colorado, Boulder, Colorado 80309, USA.,Center for Theory of Quantum Matter, University of Colorado, Boulder, Colorado 80309, USA
| | - Victor Gurarie
- Physics Department, University of Colorado, Boulder, Colorado 80309, USA.,JILA, NIST, University of Colorado, Boulder, Colorado 80309, USA.,Center for Theory of Quantum Matter, University of Colorado, Boulder, Colorado 80309, USA
| | - Ana Maria Rey
- Physics Department, University of Colorado, Boulder, Colorado 80309, USA.,JILA, NIST, University of Colorado, Boulder, Colorado 80309, USA.,Center for Theory of Quantum Matter, University of Colorado, Boulder, Colorado 80309, USA
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13
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Jenkins SD, Ruostekoski J, Javanainen J, Bourgain R, Jennewein S, Sortais YRP, Browaeys A. Optical Resonance Shifts in the Fluorescence of Thermal and Cold Atomic Gases. PHYSICAL REVIEW LETTERS 2016; 116:183601. [PMID: 27203321 DOI: 10.1103/physrevlett.116.183601] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Indexed: 06/05/2023]
Abstract
We show that the resonance shifts in the fluorescence of a cold gas of rubidium atoms substantially differ from those of thermal atomic ensembles that obey the standard continuous medium electrodynamics. The analysis is based on large-scale microscopic numerical simulations and experimental measurements of the resonance shifts in a steady-state response in light propagation.
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Affiliation(s)
- S D Jenkins
- Mathematical Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - J Ruostekoski
- Mathematical Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - J Javanainen
- Department of Physics, University of Connecticut, Storrs, Connecticut 06269-3046, USA
| | - R Bourgain
- Laboratoire Charles Fabry, Institut d'Optique, CNRS, Univ Paris Sud, 2 Avenue Augustin Fresnel, 91127 Palaiseau cedex, France
| | - S Jennewein
- Laboratoire Charles Fabry, Institut d'Optique, CNRS, Univ Paris Sud, 2 Avenue Augustin Fresnel, 91127 Palaiseau cedex, France
| | - Y R P Sortais
- Laboratoire Charles Fabry, Institut d'Optique, CNRS, Univ Paris Sud, 2 Avenue Augustin Fresnel, 91127 Palaiseau cedex, France
| | - A Browaeys
- Laboratoire Charles Fabry, Institut d'Optique, CNRS, Univ Paris Sud, 2 Avenue Augustin Fresnel, 91127 Palaiseau cedex, France
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14
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Collective atomic scattering and motional effects in a dense coherent medium. Nat Commun 2016; 7:11039. [PMID: 26984643 PMCID: PMC4800430 DOI: 10.1038/ncomms11039] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 02/15/2016] [Indexed: 11/27/2022] Open
Abstract
We investigate collective emission from coherently driven ultracold 88Sr atoms. We perform two sets of experiments using a strong and weak transition that are insensitive and sensitive, respectively, to atomic motion at 1 μK. We observe highly directional forward emission with a peak intensity that is enhanced, for the strong transition, by >103 compared with that in the transverse direction. This is accompanied by substantial broadening of spectral lines. For the weak transition, the forward enhancement is substantially reduced due to motion. Meanwhile, a density-dependent frequency shift of the weak transition (∼10% of the natural linewidth) is observed. In contrast, this shift is suppressed to <1% of the natural linewidth for the strong transition. Along the transverse direction, we observe strong polarization dependences of the fluorescence intensity and line broadening for both transitions. The measurements are reproduced with a theoretical model treating the atoms as coherent, interacting radiating dipoles. Light scattering from a dense coherent medium is determined by the interplay of dispersive and radiative dipole–dipole interactions. Here, the authors control the motional effects that obscure the coherence of scattered light and study collective emission in a driven gas of cold strontium-88 atoms.
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15
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Bettles RJ, Gardiner SA, Adams CS. Enhanced Optical Cross Section via Collective Coupling of Atomic Dipoles in a 2D Array. PHYSICAL REVIEW LETTERS 2016; 116:103602. [PMID: 27015480 DOI: 10.1103/physrevlett.116.103602] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Indexed: 06/05/2023]
Abstract
Enhancing the optical cross section is an enticing goal in light-matter interactions, due to its fundamental role in quantum and nonlinear optics. Here, we show how dipolar interactions can suppress off-axis scattering in a two-dimensional atomic array, leading to a subradiant collective mode where the optical cross section is enhanced by almost an order of magnitude. As a consequence, it is possible to attain an optical depth which implies high-fidelity extinction, from a monolayer. Using realistic experimental parameters, we also model how lattice vacancies and the atomic trapping depth affect the transmission, concluding that such high extinction should be possible, using current experimental techniques.
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Affiliation(s)
- Robert J Bettles
- Department of Physics, Joint Quantum Center (JQC) Durham-Newcastle, Durham University, South Road, Durham DH1 3LE, United Kingdom
| | - Simon A Gardiner
- Department of Physics, Joint Quantum Center (JQC) Durham-Newcastle, Durham University, South Road, Durham DH1 3LE, United Kingdom
| | - Charles S Adams
- Department of Physics, Joint Quantum Center (JQC) Durham-Newcastle, Durham University, South Road, Durham DH1 3LE, United Kingdom
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16
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Beverland ME, Alagic G, Martin MJ, Koller AP, Rey AM, Gorshkov AV. Realizing exactly solvable SU( N) magnets with thermal atoms. PHYSICAL REVIEW. A 2016; 93:10.1103/PhysRevA.93.051601. [PMID: 31276073 PMCID: PMC6604830 DOI: 10.1103/physreva.93.051601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We show that n thermal fermionic alkaline-earth-metal atoms in a flat-bottom trap allow one to robustly implement a spin model displaying two symmetries: the S n symmetry that permutes atoms occupying different vibrational levels of the trap and the SU(N) symmetry associated with N nuclear spin states. The symmetries make the model exactly solvable, which, in turn, enables the analytic study of dynamical processes such as spin diffusion in this SU(N) system. We also show how to use this system to generate entangled states that allow for Heisenberg-limited metrology. This highly symmetric spin model should be experimentally realizable even when the vibrational levels are occupied according to a high-temperature thermal or an arbitrary nonthermal distribution.
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Affiliation(s)
- Michael E Beverland
- Institute for Quantum Information & Matter, California Institute of Technology, Pasadena, California 91125, USA
| | - Gorjan Alagic
- Department of Mathematical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Michael J Martin
- Institute for Quantum Information & Matter, California Institute of Technology, Pasadena, California 91125, USA
| | - Andrew P Koller
- JILA, NIST, and Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - Ana M Rey
- JILA, NIST, and Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - Alexey V Gorshkov
- Joint Quantum Institute and Joint Center for Quantum Information and Computer Science, NIST/University of Maryland, College Park, Maryland 20742, USA
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17
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Plankensteiner D, Ostermann L, Ritsch H, Genes C. Selective protected state preparation of coupled dissipative quantum emitters. Sci Rep 2015; 5:16231. [PMID: 26549501 PMCID: PMC4637839 DOI: 10.1038/srep16231] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 10/12/2015] [Indexed: 11/20/2022] Open
Abstract
Inherent binary or collective interactions in ensembles of quantum emitters induce a spread in the energy and lifetime of their eigenstates. While this typically causes fast decay and dephasing, in many cases certain special entangled collective states with minimal decay can be found, which possess ideal properties for spectroscopy, precision measurements or information storage. We show that for a specific choice of laser frequency, power and geometry or a suitable configuration of control fields one can efficiently prepare these states. We demonstrate this by studying preparation schemes for strongly subradiant entangled states of a chain of dipole-dipole coupled emitters. The prepared state fidelity and its entanglement depth is further improved via spatial excitation phase engineering or tailored magnetic fields.
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Affiliation(s)
- D. Plankensteiner
- Institut für Theoretische Physik, Universität Innsbruck, Technikerstrasse 21a, A-6020 Innsbruck, Austria
| | - L. Ostermann
- Institut für Theoretische Physik, Universität Innsbruck, Technikerstrasse 21a, A-6020 Innsbruck, Austria
| | - H. Ritsch
- Institut für Theoretische Physik, Universität Innsbruck, Technikerstrasse 21a, A-6020 Innsbruck, Austria
| | - C. Genes
- Institut für Theoretische Physik, Universität Innsbruck, Technikerstrasse 21a, A-6020 Innsbruck, Austria
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18
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Cazalilla MA, Rey AM. Ultracold Fermi gases with emergent SU(N) symmetry. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2014; 77:124401. [PMID: 25429615 DOI: 10.1088/0034-4885/77/12/124401] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We review recent experimental and theoretical progress on ultracold alkaline-earth Fermi gases with emergent SU(N) symmetry. Emphasis is placed on describing the ground-breaking experimental achievements of recent years. The latter include (1) the cooling to below quantum degeneracy of various isotopes of ytterbium and strontium, (2) the demonstration of optical Feshbach resonances and the optical Stern-Gerlach effect, (3) the realization of a Mott insulator of (173)Yb atoms, (4) the creation of various kinds of Fermi-Bose mixtures and (5) the observation of many-body physics in optical lattice clocks. On the theory side, we survey the zoo of phases that have been predicted for both gases in a trap and loaded into an optical lattice, focusing on two and three dimensional systems. We also discuss some of the challenges that lie ahead for the realization of such phases such as reaching the temperature scale required to observe magnetic and more exotic quantum orders. The challenge of dealing with collisional relaxation of excited electronic levels is also discussed.
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Affiliation(s)
- Miguel A Cazalilla
- Department of Physics, National Tsing Hua University and National Center for Theoretical Sciences, Hsinchu City, Taiwan. Donostia International Physics Center (DIPC), Manuel de Lardizabal, 4. 20018 San Sebastian, Spain
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Pellegrino J, Bourgain R, Jennewein S, Sortais YRP, Browaeys A, Jenkins SD, Ruostekoski J. Observation of suppression of light scattering induced by dipole-dipole interactions in a cold-atom ensemble. PHYSICAL REVIEW LETTERS 2014; 113:133602. [PMID: 25302887 DOI: 10.1103/physrevlett.113.133602] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Indexed: 06/04/2023]
Abstract
We study the emergence of collective scattering in the presence of dipole-dipole interactions when we illuminate a cold cloud of rubidium atoms with a near-resonant and weak intensity laser. The size of the atomic sample is comparable to the wavelength of light. When we gradually increase the number of atoms from 1 to ~450, we observe a broadening of the line, a small redshift and, consistently with these, a strong suppression of the scattered light with respect to the noninteracting atom case. We compare our data to numerical simulations of the optical response, which include the internal level structure of the atoms.
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Affiliation(s)
- J Pellegrino
- Laboratoire Charles Fabry, Institut d'Optique, CNRS, Université Paris Sud, 2 Avenue Augustin Fresnel, 91127 Palaiseau cedex, France
| | - R Bourgain
- Laboratoire Charles Fabry, Institut d'Optique, CNRS, Université Paris Sud, 2 Avenue Augustin Fresnel, 91127 Palaiseau cedex, France
| | - S Jennewein
- Laboratoire Charles Fabry, Institut d'Optique, CNRS, Université Paris Sud, 2 Avenue Augustin Fresnel, 91127 Palaiseau cedex, France
| | - Y R P Sortais
- Laboratoire Charles Fabry, Institut d'Optique, CNRS, Université Paris Sud, 2 Avenue Augustin Fresnel, 91127 Palaiseau cedex, France
| | - A Browaeys
- Laboratoire Charles Fabry, Institut d'Optique, CNRS, Université Paris Sud, 2 Avenue Augustin Fresnel, 91127 Palaiseau cedex, France
| | - S D Jenkins
- Mathematical Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - J Ruostekoski
- Mathematical Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
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Gil LIR, Mukherjee R, Bridge EM, Jones MPA, Pohl T. Spin squeezing in a Rydberg lattice clock. PHYSICAL REVIEW LETTERS 2014; 112:103601. [PMID: 24679291 DOI: 10.1103/physrevlett.112.103601] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Indexed: 06/03/2023]
Abstract
We theoretically demonstrate a viable approach to spin squeezing in optical lattice clocks via optical dressing of one clock state to a highly excited Rydberg state, generating switchable atomic interactions. For realistic experimental parameters, these interactions are shown to generate over 10 dB of squeezing in large ensembles within a few microseconds and without degrading the subsequent clock interrogation.
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Affiliation(s)
- L I R Gil
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Strasse 38, 01187 Dresden, Germany
| | - R Mukherjee
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Strasse 38, 01187 Dresden, Germany
| | - E M Bridge
- Joint Quantum Centre (JQC) Durham-Newcastle, Department of Physics, Durham University, Durham DH1 3LE, United Kingdom
| | - M P A Jones
- Joint Quantum Centre (JQC) Durham-Newcastle, Department of Physics, Durham University, Durham DH1 3LE, United Kingdom
| | - T Pohl
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Strasse 38, 01187 Dresden, Germany
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Eisert J, van den Worm M, Manmana SR, Kastner M. Breakdown of quasilocality in long-range quantum lattice models. PHYSICAL REVIEW LETTERS 2013; 111:260401. [PMID: 24483785 DOI: 10.1103/physrevlett.111.260401] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Indexed: 06/03/2023]
Abstract
We study the nonequilibrium dynamics of correlations in quantum lattice models in the presence of long-range interactions decaying asymptotically as a power law. For exponents larger than the lattice dimensionality, a Lieb-Robinson-type bound effectively restricts the spreading of correlations to a causal region, but allows supersonic propagation. We show that this decay is not only sufficient but also necessary. Using tools of quantum metrology, for any exponents smaller than the lattice dimension, we construct Hamiltonians giving rise to quantum channels with capacities not restricted to a causal region. An analytical analysis of long-range Ising models illustrates the disappearance of the causal region and the creation of correlations becoming distance independent. Numerical results obtained using matrix product state methods for the XXZ spin chain reveal the presence of a sound cone for large exponents and supersonic propagation for small ones. In all models we analyzed, the fast spreading of correlations follows a power law, but not the exponential increase of the long-range Lieb-Robinson bound.
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Affiliation(s)
- Jens Eisert
- Dahlem Center for Complex Quantum Systems, Freie Universität Berlin, 14195 Berlin, Germany
| | - Mauritz van den Worm
- Institute of Theoretical Physics, University of Stellenbosch, Stellenbosch 7600, South Africa and National Institute for Theoretical Physics (NITheP), Stellenbosch 7600, South Africa
| | - Salvatore R Manmana
- Institute for Theoretical Physics, Georg-August-Universität Göttingen, 37077 Göttingen, Germany
| | - Michael Kastner
- Institute of Theoretical Physics, University of Stellenbosch, Stellenbosch 7600, South Africa and National Institute for Theoretical Physics (NITheP), Stellenbosch 7600, South Africa
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