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arXiv:1903.12313 · Physical review. B./Physical review. B

Decoherence and collective effects of quantum emitters near a medium at criticality

F. M. D'Angelis, F. A. Pinheiro, François Impens

Published May 28, 2019• 4 citations
arXivHTMLPDF

Abstract

We investigate the influence of phase transitions on the behavior of collective quantum emission. We discuss two distinct physical processes, the center-of-mass decoherence of a single emitter, and the collective emission of two emitters, addressed with an unified formalism relying on standard perturbation theory. Two specific examples of phase transitions are considered: the percolation transition in a metal-dielectric composite, and the metal-insulator transition in ${\mathrm{VO}}_{2}$. The decoherence and the collective emission rates can be decomposed as a sum of two contributions, accounting for the spontaneous emission and for interference effects, respectively. The former is enhanced by the Purcell effect for emitter(s) in the vicinity of the critical medium. The latter, associated with quantum interferences, experiences a ``sudden death'' near the critical point of the phase transition. Our findings unveil the interplay between the Purcell and collective effects and its dependence on metal-insulator transitions. In the case of ${\mathrm{VO}}_{2}$, decoherence and collective emission rates exhibit a characteristic hysteresis that strongly depends on the material temperature. These results, based on experimental data, suggest that ${\mathrm{VO}}_{2}$ could be explored as a versatile material platform where decoherence and collective emission can be tuned by varying the temperature.

DOI
10.1103/physrevb.99.195451

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