Renormalization group study of Bose polarons

We study the properties of a single impurity in a dilute Bose gas, a Bose polaron, using the functional renormalization group. We use an ansatz for the effective action motivated by a derivative expansion, and we compute the energies of the attractive and repulsive branches of excitations in both tw...

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Bibliographic Details
Published in:arXiv.org 2021-08
Main Authors: Isaule, Felipe, Morera, Ivan, Massignan, Pietro, Juliá-Díaz, Bruno
Format: Article
Language:English
Subjects:
Bosons
Couplings
Impurities
Polarons
Online Access:Get full text
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Summary:We study the properties of a single impurity in a dilute Bose gas, a Bose polaron, using the functional renormalization group. We use an ansatz for the effective action motivated by a derivative expansion, and we compute the energies of the attractive and repulsive branches of excitations in both two and three spatial dimensions. Three-body correlations play an important role in the attractive branch, and we account for those by including three-body couplings between two bath bosons and the impurity. Our calculations compare very favorably with state-of-the-art experimental measurements and numerical simulations.
ISSN:2331-8422
DOI:10.48550/arxiv.2105.10801