The new physics of non-equilibrium condensates: insights from classical dynamics
| Autor: | Paul R. Eastham |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Physics
Condensed Matter::Quantum Gases Condensed Matter - Mesoscale and Nanoscale Physics Strongly Correlated Electrons (cond-mat.str-el) Scattering Physics beyond the Standard Model FOS: Physical sciences Normal state Dissipation Condensed Matter Physics Condensed Matter - Strongly Correlated Electrons Mesoscale and Nanoscale Physics (cond-mat.mes-hall) Polariton Coherent states General Materials Science Statistical physics Randomness Coherence (physics) |
| DOI: | 10.48550/arxiv.cond-mat/0609169 |
| Popis: | We discuss the dynamics of classical Dicke-type models, aiming to clarify the mechanisms by which coherent states could develop in potentially non-equilibrium systems such as semiconductor microcavities. We present simulations of an undamped model which show spontaneous coherent states with persistent oscillations in the magnitude of the order parameter. These states are generalisations of superradiant ringing to the case of inhomogeneous broadening. They correspond to the persistent gap oscillations proposed in fermionic atomic condensates, and arise from a variety of initial conditions. We show that introducing randomness into the couplings can suppress the oscillations, leading to a limiting dynamics with a time-independent order parameter. This demonstrates that non-equilibrium generalisations of polariton condensates can be created even without dissipation. We explain the dynamical origins of the coherence in terms of instabilities of the normal state, and consider how it can additionally develop through scattering and dissipation. Comment: 10 pages, 4 figures, submitted for a special issue of J. Phys.: Condensed Matter on "Optical coherence and collective phenomena in nanostructures". v2: added discussion of links to exact solutions |
| Databáze: | OpenAIRE |
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