SEMINAR+WEBINAR ANNOUNCEMENT

SEMINAR+WEBINAR ANNOUNCEMENT
Thursday, 21st of July 2022 at 11:30
UPC campus nord, B4-212 (aula seminari)
https://meet.google.com/whq-mkve-aja

Nikolay Yegovtsev

Department of Physics

University of Colorado

Boulder CO

“Strongly interacting impurities
in a dilute Bose condensate”

Abstract
An impurity in a Bose gas is commonly referred to as Bose polaron. For a dilute Bose gas its properties are expected to be universal, that is dependent only on a few parameters characterizing the boson-impurity interactions. When boson-impurity interactions are weak, it has been known for some time that the properties of the polaron depend only on the scattering length of these interactions. In this talk I will examine stronger boson-impurity interactions, keeping their range finite. It will be demonstrated that for attractive interactions between impurity and the bosons up to and including the unitary point of these interactions, all static properties of a Bose polaron in a dilute Bose gas can be calculated in terms of the scattering length and an additional parameter which characterizes the range of the impurity-boson interactions. One can produce explicit expressions for the energy and other properties of polaron for the case when the impurity-boson scattering length is tuned to unitarity. I will also discuss the first order correction in inverse powers of the impurity-boson scattering length around the unitary point.

Bibliography

[1] Pietro Massignan, Nikolay Yegovtsev, and Victor Gurarie “Universal Aspects of a Strongly Interacting Impurity in a Dilute Bose Condensate” Phys. Rev. Lett. 126, 123403 (2021)

[2] Nikolay Yegovtsev, Pietro Massignan, Victor Gurarie “Strongly interacting impurities in a dilute Bose condensate” arXiv:2201.04295