Validity of the Fr\"ohlich model for a mobile impurity in a Bose-Einstein condensate
Quantum Gases
2025-11-24 v3 Mathematical Physics
math.MP
Abstract
We analyze the many-body Hamiltonian describing a mobile impurity immersed in a Bose-Einstein condensate (BEC). Using exact unitary transformations and rigorous error estimates, we show the validity of the Bogoliubov-Fr\"ohlich Hamiltonian for the Bose polaron in the regime of moderately strong, repulsive interactions with a dilute BEC. Moreover, we calculate analytically the universal logarithmic correction to the ground state energy that arises from an impurity mediated phonon-phonon interaction.
Keywords
Cite
@article{arxiv.2411.11655,
title = {Validity of the Fr\"ohlich model for a mobile impurity in a Bose-Einstein condensate},
author = {Jonas Lampart and Arnaud Triay},
journal= {arXiv preprint arXiv:2411.11655},
year = {2025}
}