Quasiparticle properties of long-range impurities in a Bose condensate

Date

2025-12-01

Author

Yoğurt, Taha Alper
Eiles, Matthew T.

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

47
views

10
downloads

Cite This

An impurity immersed in a Bose condensate can form a quasiparticle known as a Bose polaron. When the impurity-boson interaction is short ranged and three-body Efimov correlations are neglected, the quasiparticle properties can be characterized in terms of the impurity-boson scattering length aIB and the condensate coherence length xi. This description remains valid irrespective of the bath density n(0). Long-ranged interactions-such as provided by Rydberg or ionic impurities-introduce an effective interaction range r(eff) as the third length scale. The interplay among these competing length scales raises the question of whether a robust description across different bath densities can still be maintained. In this study, we discuss the quasiparticle nature of long-range impurities and its dependence on the length scales n(0)(-1/3), r(eff), and xi. We employ two complementary theories-the coherent-state ansatz and the perturbative Gross-Pitaevskii theory-which incorporate beyond-Frohlich interactions. We derive an analytical expression for the beyond-Frohlich effective mass for a contact interaction and numerically compute the effective mass for long-range impurities. We argue that the coupling parameter |a(IB)|n(0)(1/3) remains the principal parameter governing the properties of the polaron. For weak (|a(IB)|n(0)(1/3)> 1).

URI

https://hdl.handle.net/11511/118644

Collections

Department of Physics, Article