Mobile impurity in a Bose-Einstein condensate and the orthogonality catastrophe

We analyze the properties of an impurity in a dilute Bose-Einstein condensate (BEC). First the quasiparticle residue of a static impurity in an ideal BEC is shown to vanish with increasing particle number as a stretched exponential, leading to a bosonic orthogonality catastrophe. Then we introduce a...

Full description

Saved in:
Bibliographic Details
Published in:arXiv.org 2020-04
Main Authors: Nils-Eric Guenther, Schmidt, Richard, Bruun, Georg M, Gurarie, Victor, Massignan, Pietro
Format: Article
Language:English
Subjects:
Bose-Einstein condensates
Impurities
Matter & antimatter
Orthogonality
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We analyze the properties of an impurity in a dilute Bose-Einstein condensate (BEC). First the quasiparticle residue of a static impurity in an ideal BEC is shown to vanish with increasing particle number as a stretched exponential, leading to a bosonic orthogonality catastrophe. Then we introduce a variational ansatz, which recovers this exact result and describes the macroscopic dressing of the impurity including its back-action onto the BEC as well as boson-boson repulsion beyond the Bogoliubov approximation. This ansatz predicts that the orthogonality catastrophe also occurs for mobile impurities, whenever the BEC becomes ideal. Finally, we show that our ansatz agrees well with experimental results.
ISSN:2331-8422
DOI:10.48550/arxiv.2004.07166