Work

Contrasting quantum and classical scaling of the effective mass of the charged polaron

Year: 2026

Type: article

Abstract: We consider the problem of a charged impurity exerting a weak, slowly decaying force on its surroundings, treating the latter as an ideal compressible fluid. In the semiclassical approximation, the ion is described by the Newton equation coupled to the Euler equation for the medium. After linearization, we obtain a simple closed formula for the effective mass of the impurity, depending on the interaction potential, the mean medium density, and sound velocity. Thus, once the interaction and the equation of state of the fluid is known, an estimate of the hydrodynamic effective mass can be quickly provided. Going beyond the classical case, we show that replacing the Newton with Schrödinger equation induces a different mass renormalization, wherein the surroundings affect the dynamics of the dispersion of the particle’s wave packet. The two effective masses may remarkably differ, in particular, the scaling of the two Fermi polaron effective masses with the medium density is opposite. Our results are relevant for experimental systems featuring low energy impurities in Fermi or Bose systems, such as ions immersed in neutral atomic gases.

Source: Journal of Physics A Mathematical and Theoretical

DOI: 10.1088/1751-8121/ae5098

Authors: Krzysztof Myśliwy, Piotr Wysocki, Krzysztof Jachymski

Institution: University of Warsaw

Language: English

Topic: Cold Atom Physics and Bose-Einstein Condensates

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,325

Funder: Narodowe Centrum Nauki