Abstract

Fluctuation and dissipation are byproducts of coupling to the "environment." The Caldeira-Leggett model, a successful paradigm of quantum Brownian motion, views the environment as a collection of harmonic oscillators linearly coupled to the system. However, symmetry considerations may forbid a linear coupling, e.g., for a neutral particle in quantum electrodynamics. We argue that the absence of linear couplings can lead to a fundamentally different behavior. Specifically, we consider a heavy particle quadratically coupled to quantum fluctuations of the bath. In one dimension the particle undergoes anomalous diffusion, unfolding as a power-law distribution in space, reminiscent of Levy flights. We suggest condensed matter analogs where similar effects may arise.

Publication Details
Publication Type
Journal Article
Year of Publication
2016
Volume
93
DOI
10.1103/PhysRevB.93.014309
Journal
Physical Review B
Contributors
Groups
Date Published
01/2016