Flight of a heavy particle nonlinearly coupled to a quantum bath
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 Lévy flights. We suggest condensed matter analogs where similar effects may arise.
- Publication:
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Physical Review B
- Pub Date:
- January 2016
- DOI:
- 10.1103/PhysRevB.93.014309
- arXiv:
- arXiv:1508.00582
- Bibcode:
- 2016PhRvB..93a4309M
- Keywords:
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- Quantum Physics;
- Condensed Matter - Statistical Mechanics;
- Condensed Matter - Strongly Correlated Electrons
- E-Print:
- Introduction expanded. Appendices added