Finite-temperature entanglement and coherence in asymmetric bosonic Josephson junctions
Year: 2025
Authors: Vianello C., Ferraretto M., Salasnich L.
Autors Affiliation: Univ Padua, Dipartimento Fis & Astron Galileo Galilei, Via Marzolo 8, I-35131 Padua, Italy; Ist Nazl Fis Nucleare, Sez Padova, Via Marzolo 8, I-35131 Padua, Italy; Scuola Int Super Studi Avanzati, Via Bonomea 265, I-34136 Trieste, Italy; Univ Padua, Padua QTech Ctr, Via Gradenigo 6-A, I-35131 Padua, Italy; Ist Nazl Ottica Consiglio Nazl Ric, Via Carrara 1, I-50019 Sesto Fiorentino, Italy.
Abstract: We investigate the finite-temperature properties of a bosonic Josephson junction composed of N interacting atoms confined by a quasi-one-dimensional asymmetric double-well potential, modeled by the two-site Bose-Hubbard Hamiltonian. We numerically compute the spectral decomposition of the statistical ensemble of states, the thermodynamic and entanglement entropies, the population imbalance, the quantum Fisher information, and the coherence visibility. We analyze their dependence on the system parameters, showing, in particular, how finite temperature and on-site energy asymmetry affect the entanglement and coherence properties of the system. Moreover, starting from a quantum phase model which accurately describes the system over a wide range of interactions, we develop a reliable description of the strong tunneling regime, where thermal averages may be computed analytically using a modified Boltzmann weight involving an effective temperature. We discuss the possibility of applying this effective description to other models in suitable regimes.
Journal/Review: PHYSICAL REVIEW A
Volume: 111 (6) Pages from: 63310-1 to: 63310-13
More Information: C.V. and L.S. are supported by Iniziativa Specifica Quantum of INFN and by the Project Frontiere Quantistiche (Dipartimenti di Eccellenza) of the Italian Ministry of University and Research (MUR) . M.F. acknowledges the SISSA and Massimo Capone for support. L.S. is partially supported by funds of the European Union-Next Generation EU: European Quantum Flagship Project PASQuanS2, National Center for HPC, Big Data and Quantum Computing [Spoke 10: Quantum Computing] . L.S. also acknowledges the PRIN Project Quantum Atomic Mixtures: Droplets, Topological Structures, and Vortices of MUR.KeyWords: Bose-einstein Condensate; Quantum Dynamics; StatesDOI: 10.1103/v6xk-3xsh
