Ultra-Dilute Gas of Polarons in a Bose–Einstein Condensate

authored by

Luis A.Peña Ardila

Abstract

We investigate the properties of a dilute gas of impurities embedded in an ultracold gas of bosons that forms a Bose–Einstein condensate (BEC). This work focuses mainly on the equation of state (EoS) of the impurity gas at zero temperature and the induced interaction between impurities mediated by the host bath. We use perturbative field-theory approaches, such as Hugenholtz– Pines formalism, in the weakly interacting regime. In turn, for strong interactions, we aim at non-perturbative techniques such as quantum–Monte Carlo (QMC) methods. Our findings agree with experimental observations for an ultra dilute gas of impurities, modeled in the framework of the single impurity problem; however, as the density of impurities increases, systematic deviations are displayed with respect to the one-body Bose polaron problem.

Organisation(s)

Institute of Theoretical Physics
QuantumFrontiers

Type

Article

Journal

Atoms

Volume

10

Publication date

02.03.2022

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Atomic and Molecular Physics, and Optics, Nuclear and High Energy Physics, Condensed Matter Physics

Electronic version(s)

https://doi.org/10.3390/atoms10010029 (Access: Open)