2018/06/28 by Matteo Biondi, Saskia Lienhard, Gianni Blatter +1
Physics and Astronomy · #Antiferromagnetism #Coherence (philosophical gambling strategy) #Cold Atom Physics and Bose-Einstein Condensates #Dissipative system #Instability #Lattice (music) #Nonlinear Photonic Systems #Photon #Quantum #Quantum fluctuation #Strong Light-Matter Interactions #cond-mat.quant-gas
paper · pdf · doi:10.1088/1402-4896/aaf120
7 pages, 3 figures, submitted to Physica Scripta as part of the Focus Issue: Quantum Optics and Beyond - in honour of Wolfgang Schleich
arxiv created 2018/06/28 · openalex created_date 2018/07/10 · openalex publication_date 2018/11/15 · arxiv updated 2019/05/22 · openalex updated_date 2026/08/05
Abstract The driven, dissipative Bose–Hubbard model (BHM) provides a generic description of collective phases of interacting photons in cavity arrays. In the limit of strong optical nonlinearities (hard-core limit), the BHM maps on the dissipative, transverse-field XY model (XYM). The steady-state of the XYM can be analyzed using mean-field theory, which reveals a plethora of interesting dynamical phenomena. For example, strong hopping combined with a blue-detuned drive, leads to an instability of the homogeneous steady-state with respect to antiferromagnetic fluctuations. In this paper, we address the question whether such an antiferromagnetic instability survives in the presence of quantum correlations beyond the mean-field approximation. For that purpose, we employ a self-consistent 1/ z expansion for the density matrix, where z is the lattice coordination number, i.e. the number of nearest neighbors for each site. We show that quantum fluctuations stabilize a new homogeneous steady-state with antiferromagnetic correlations in agreement with exact numerical simulations for finite lattices. The latter manifests itself as short-ranged oscillations of the first and second-order spatial coherence functions of the photons emitted by the array.