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arXiv · 1508.00582

Flight of a heavy particle nonlinearly coupled to a quantum bath

Mohammad F. Maghrebi·Matthias Krüger·Mehran Kardar
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Abstract

Fluctuation and dissipation are by-products 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 nonlinear 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 Lévy flights. We suggest condensed matter analogs where similar effects may arise.

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Mohammad F. Maghrebi, Matthias Krüger, Mehran Kardar. 2016-04-26. Flight of a heavy particle nonlinearly coupled to a quantum bath. https://doi.org/10.1103/physrevb.93.014309

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