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arXiv · 2411.11655

Validity of the Fr\"ohlich model for a mobile impurity in a Bose-Einstein condensate

Jonas Lampart·Arnaud Triay
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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.

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Jonas Lampart, Arnaud Triay. 2024-11-18. Validity of the Fr\"ohlich model for a mobile impurity in a Bose-Einstein condensate. https://doi.org/10.1103/3zd3-rxhp

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