Dynamical Equilibration Across a Quenched Phase Transition in a Trapped Quantum Gas

• Published in: arXiv.org
• Main Authors: I -K Liu, Donadello, S, Lamporesi, G, Ferrari, G, S -C Gou, Dalfovo, F, Proukakis, N P
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 21.12.2017
• Subjects: Balancing; Decoupling; Defects; Equilibrium; Granulation; Phase transitions; Physics - Quantum Gases; Scaling laws
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1712.08074

The formation of an equilibrium quantum state from an uncorrelated thermal one through the dynamical crossing of a phase transition is a central question of non-equilibrium many-body physics. During such crossing, the system breaks its symmetry by establishing numerous uncorrelated regions separated by spontaneously-generated defects, whose emergence obeys a universal scaling law with the quench duration. Much less is known about the ensuing re-equilibrating or "coarse-graining" stage, which is governed by the evolution and interactions of such defects under system-specific and external constraints. In this work we perform a detailed numerical characterization of the entire non-equilibrium process, addressing subtle issues in condensate growth dynamics and demonstrating the quench-induced decoupling of number and coherence growth during the re-equilibration process. Our unique visualizations not only reproduce experimental measurements in the relevant regimes, but also provide valuable information in currently experimentally-inaccessible regimes.