Non-equilibrium Dynamics of a Double-well Bose–Einstein Condensate-dual Reservoir System

• Published in: Brazilian journal of physics 2021-08, Vol.51 (4), p.944-953
• Main Authors: Rajagopal, Kalai K., Ibragimov, Gafurjan
• Format: Article
• Language: English
• Subjects: Atomic Physics; Bose-Einstein condensates; Entanglement; Josephson junctions; Particle interactions; Physical properties; Physics; Physics and Astronomy; Reservoirs
• ISSN: 0103-9733; 1678-4448
• DOI: 10.1007/s13538-021-00904-9

We have studied the dynamics of a two-site Bose–Einstein condensate subject to tunnelling coupling (which makes the system a bosonic Josephson junction), having on-site inter-particle interaction (making the system a small Bose–Hubbard model) and in contact with two separate heat baths, which makes the system lossy and potentially drives it into a non-equilibrium state with some heat current. The dynamical calculation of the system is done within the standard quantum generalized Langevin setting, and the heat baths are assumed to have non-zero memory time (Ornstein–Uhlenbeck process). We numerically calculated the time evolution of the population imbalance, coherence and entanglement of the system. We have shown inter-particle interaction, noise and dissipation induced by BEC atoms-reservoir interaction that are crucial in affecting the dynamics of the mentioned physical parameters. The study also indicates that quantumness (non-classicality) of the system is characterized by the interplay between dissipation and inter-particle interaction.