Analyzing a Bose polaron across resonant interactions
Abstract
Recently, two independent experiments reported the observation of long-lived polarons in a Bose-Einstein condensate, providing an excellent setting to study the generic scenario of a mobile impurity interacting with a quantum reservoir. Here, we expand the experimental analysis by disentangling the effects of trap inhomogeneities and the many-body continuum in one of these experiments. This makes it possible to extract the energy of the polaron at a well-defined density as a function of the interaction strength. Comparisons with quantum Monte-Carlo as well as diagrammatic calculations show good agreement, and provide a more detailed picture of the polaron properties at stronger interactions than previously possible. Moreover, we develop a semi-classical theory for the motional dynamics and three-body loss of the polarons, which partly explains a previously unresolved discrepancy between theory and experimental observations for repulsive interactions. Finally, we utilize quantum Monte-Carlo calculations to demonstrate that the findings reported in the two experiments are consistent with each other.
Cite
@article{arxiv.1812.04609,
title = {Analyzing a Bose polaron across resonant interactions},
author = {L. A. Peña Ardila and N. B. Jörgensen and T. Pohl and S. Giorgini and G. M. Bruun and J. J. Arlt},
journal= {arXiv preprint arXiv:1812.04609},
year = {2019}
}