Low temperature properties of a quantum particle coupled to dissipative environments

TL;DR

This paper investigates how a quantum particle's behavior in dissipative environments varies with coupling strength, revealing phenomena like effective mass formation, divergence, and localization transitions at low temperatures.

Contribution

It provides a comparative analysis of different dissipative environments, highlighting conditions leading to effective mass and localization transitions in quantum particles.

Findings

Effective mass describes particle dynamics in some environments.

Divergence of effective mass suppresses quantum effects in others.

Localization transitions occur with weak potentials and specific couplings.

Abstract

We study the dynamics of a quantum particle coupled to dissipative (ohmic) environments, such as an electron liquid. For some choices of couplings, the properties of the particle can be described in terms of an effective mass. A particular case is the three dimensional dirty electron liquid. In other environments, like the one described by the Caldeira-Leggett model, the effective mass diverges at low temperatures, and quantum effects are strongly suppressed. For interactions within this class, arbitrarily weak potentials lead to localized solutions. Particles bound to external potentials, or moving in closed orbits, can show a first order transition, between strongly and weakly localized regimes.