Quantum Cherenkov transition of finite momentum Bose polarons
Abstract
We investigate the behavior of a finitemomentum impurity immersed in a weakly interacting threedimensional BoseEinstein condensate (BEC) of ultracold atoms, giving a detailed account of the dynamical quantum Cherenkov transition discussed in Ref. [arXiv:2101.00030]. Using a timedependent variational approach, we identify a transition in the farfromequilibrium dynamics of the system after the attractive shortrange impurityboson interaction is quenched on. The transition occurs as the impurity's velocity crosses an interactiondependent critical value, and manifests in the longtime behavior of the Loschmidt echo and average impurity velocity. This behavior is also reflected in the finite momentum ground state of the system, where the group velocity of the interactiondressed impurity loses it's dependence on the total momentum of the system as the critical point is crossed. The transition we discuss should be experimentally observable via a variety of common protocols in ultracold atomic systems such as timeofflight imaging, RF spectroscopy, Ramsey interferometry, and absorption imaging.
 Publication:

arXiv eprints
 Pub Date:
 September 2021
 arXiv:
 arXiv:2109.12260
 Bibcode:
 2021arXiv210912260S
 Keywords:

 Condensed Matter  Quantum Gases;
 Quantum Physics
 EPrint:
 15 pages, 7 figures