Observation of quasiparticle pair-production and quantum entanglement in atomic quantum gases quenched to an attractive interaction
Authors: Cheng-An Chen, Sergei Khlebnikov, Chen-Lung Hung
Journal Ref: arXiv:2102.11215; Phys. Rev. Lett. 127, 060404 (2021)
Predicting the dynamics of many-body systems far from equilibrium is a challenging theoretical problem. A long-predicted phenomenon in hydrodynamic nonequilibrium systems is the occurrence of Sakharov oscillations, which manifest in the anisotropy of the cosmic microwave background and the large-scale correlations of galaxies. Here, we report the observation of Sakharov oscillations in the density fluctuations of a quenched atomic superfluid through a systematic study in both space and time domains and with tunable interaction strengths. Our work suggests a different approach to the study of nonequilibrium dynamics of quantum many-body systems and the exploration of their analogs in cosmology and astrophysics.