Séminaire du LPTMS: Alberto Biella

Efficient stochastic unraveling of disordered open quantum systems

Alberto Biella (Laboratoire Matériaux et Phénomènes Quantiques, Université Paris Diderot)

The interplay of interaction, dissipation and driving in open quantum systems can trigger transitions between nonequilibrium phases. Such behaviour can emerge in extended lattices, in more then one spatial dimension, when homogenous systems are considered. However, in any realistic experimental realization, disorder cannot be neglected. In this work we develop a method to efficiently unravel the density matrix of a generic disordered open quantum system exploiting stochastic trajectories. We use it to study the effect of on-site disorder in the paradigmatic driven-dissipative Bose-Hubbard lattice in two dimensions. In particular, we will focus on the role of the disorder when the system is driven across a first-order transition from the low- to the high-density phase. We found that the disorder induces the formation of density domains which progressively smears the sharp transition leading to a crossover behaviour in the thermodynamic limit. We characterize this mechanism in terms of photon density and spatial correlation functions and we discuss how inhomogeneities affects the bistable dynamics of the system at the transition. Our results are relevant for state-of-the-art experiments in extended photonic lattices based on semiconductor microcavities and superconducting circuits.


Date/Time : 30/10/2018 - 11:00 - 12:00

Location : LPTMS, salle 201, 2ème étage, Bât 100, Campus d'Orsay

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