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Quantum-optical magnets with competing short- and long-range interactions: Rydberg-dressed spin lattice in an optical cavity

by Jan Gelhausen, Michael Buchhold, Achim Rosch, Philipp Strack

Submission summary

As Contributors: Jan Gelhausen · Achim Rosch
Arxiv Link: http://arxiv.org/abs/1608.01319v2
Date accepted: 2016-10-18
Date submitted: 2016-10-14
Submitted by: Gelhausen, Jan
Submitted to: SciPost Physics
Discipline: Physics
Subject area: Quantum Physics
Approach: Theoretical

Abstract

The fields of quantum simulation with cold atoms [1] and quantum optics [2] are currently being merged. In a set of recent pathbreaking experiments with atoms in optical cavities [3,4] lattice quantum many-body systems with both, a short-range interaction and a strong interaction potential of infinite range -mediated by a quantized optical light field- were realized. A theoretical modelling of these systems faces considerable complexity at the interface of: (i) spontaneous symmetry-breaking and emergent phases of interacting many-body systems with a large number of atoms $N\rightarrow\infty$, (ii) quantum optics and the dynamics of fluctuating light fields, and (iii) non-equilibrium physics of driven, open quantum systems. Here we propose what is possibly the simplest, quantum-optical magnet with competing short- and long-range interactions, in which all three elements can be analyzed comprehensively: a Rydberg-dressed spin lattice [5] coherently coupled to a single photon mode. Solving a set of coupled even-odd sublattice Master equations for atomic spin and photon mean-field amplitudes, we find three key results. (R1): Superradiance and a coherent photon field can coexist with spontaneously broken magnetic translation symmetry. The latter is induced by the short-range nearest-neighbor interaction from weakly admixed Rydberg levels. (R2): This broken even-odd sublattice symmetry leaves its imprint in the light via a novel peak in the cavity spectrum beyond the conventional polariton modes. (R3): The combined effect of atomic spontaneous emission, drive, and interactions can lead to phases with anomalous photon number oscillations. Extensions of our work include nano-photonic crystals coupled to interacting atoms and multi-mode photon dynamics in Rydberg systems.

Ontology / Topics

See full Ontology or Topics database.

Emergent phases Long-range interactions Nanophotonic crystals Open quantum systems Optical cavities Polaritons Quantum optics Quantum simulation Rydberg atoms Spontaneous symmetry breaking Superradiance Ultracold atoms

Published as SciPost Phys. 1, 004 (2016)



Author comments upon resubmission

We have addressed all points mentioned by the referees and have supplied a detailed response to every referee report. We are thankful for the referees suggestions and we believe that with these changes made our manuscript has benefitted in terms of clarity.

List of changes

added appendix C (Validity analysis of the even-odd sub lattice Ansatz), added appendix D (Hierarchy of energy scales and problematic Rydberg decays), added Sec IVD (Discussion of beyond mean-field effects), added references to various driven-dissipative lattice models

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