Quantum synchronisation enabled by dynamical symmetries and dissipation

Autor: J Tindall, C Sánchez Muñoz, B Buča, D Jaksch
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: New Journal of Physics, Vol 22, Iss 1, p 013026 (2020)
Druh dokumentu: article
ISSN: 1367-2630
DOI: 10.1088/1367-2630/ab60f5
Popis: In nature, instances of synchronisation abound across a diverse range of environments. In the quantum regime, however, synchronisation is typically observed by identifying an appropriate parameter regime in a specific system. In this work we show that this need not be the case, identifying conditions which, when satisfied, guarantee that the individual constituents of a generic open quantum system will undergo completely synchronous limit cycles which are, to first order, robust to symmetry-breaking perturbations. We then describe how these conditions can be satisfied by the interplay between several elements: interactions, local dephasing and the presence of a strong dynamical symmetry—an operator which guarantees long-time non-stationary dynamics. These elements cause the formation of entanglement and off-diagonal long-range order which drive the synchronised response of the system. To illustrate these ideas we present two central examples: a chain of quadratically dephased spin-1s and the many-body charge-dephased Hubbard model. In both cases perfect phase-locking occurs throughout the system, regardless of the specific microscopic parameters or initial states. Furthermore, when these systems are perturbed, their nonlinear responses elicit long-lived signatures of both phase and frequency-locking.
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