Fate of an impurity strongly interacting with a thermal Bose gas
Abstract
We spectroscopically study mobile impurities immersed in a homogeneous bosonic bath (a box-trapped Bose gas), varying the bath temperature and the strength of impurity-bath interactions. We compare our results to those for a quasipure Bose-Einstein condensate (BEC), and find that for strong impurity-bath interactions, the spectra narrow with increasing temperature, while the impurity energy shift is suppressed. Near the critical temperature for condensation, many-body effects still play an important role, and only for a nondegenerate bath, the system approaches the classical Boltzmann-gas behavior. The key spectral features are reproduced within the theory of an ideal Bose polaron.
Cite
@article{arxiv.2508.06493,
title = {Fate of an impurity strongly interacting with a thermal Bose gas},
author = {Jiří Etrych and Sebastian J. Morris and Simon M. Fischer and Gevorg Martirosyan and Christopher J. Ho and Moritz Drescher and Manfred Salmhofer and Zoran Hadzibabic and Tilman Enss and Christoph Eigen},
journal= {arXiv preprint arXiv:2508.06493},
year = {2025}
}
Comments
Main Text (5 pages, 3 figures), Supplemental Material (2 pages, 3 figures)