Early-time dynamics of Bose gases quenched into the strongly interacting regime

A. Muñoz de las Heras, M. M. Parish, F. M. Marchetti

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3 Citations (Scopus)

Abstract

We study the early-time dynamics of a degenerate Bose gas after a sudden quench of the interaction strength, starting from a weakly interacting gas. By making use of a time-dependent generalization of the Nozières-Saint-James variational formalism, we describe the crossover of the early-time dynamics from shallow to deep interaction quenches. We analyze the coherent oscillations that characterize both the density of excited states and the Tan's contact as a function of the final scattering length. For shallow quenches, the oscillatory behavior is negligible and the dynamics is universally governed by the healing length and the mean-field interaction energy. By increasing the final scattering length to intermediate values, we reveal a universal regime where the period of the coherent atom-molecule oscillations is set by the molecule binding energy. For the largest scattering lengths we can numerically simulate in the unitary regime, we find a universal scaling behavior of the typical growth time of the momentum distribution in agreement with recent experimental observations [C. Eigen et al., Nature 563, 221 (2018)10.1038/s41586-018-0674-1].

Original languageEnglish
Article number023623
Number of pages10
JournalPhysical Review A
Volume99
Issue number2
DOIs
Publication statusPublished - 21 Feb 2019

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