Directional Goldstone waves in polariton condensates close to equilibrium
Open Access
- 10 January 2020
- journal article
- research article
- Published by Springer Science and Business Media LLC in Nature Communications
- Vol. 11 (1), 1-7
- https://doi.org/10.1038/s41467-019-13733-x
Abstract
Quantum fluids of light are realized in semiconductor microcavities using exciton-polaritons, solid-state quasi-particles with a light mass and sizeable interactions. Here, we use the microscopic analogue of oceanographic techniques to measure the excitation spectrum of a thermalised polariton condensate. Increasing the fluid density, we demonstrate the transition from a free-particle parabolic dispersion to a linear, sound-like Goldstone mode characteristic of superfluids at equilibrium. Notably, we reveal the effect of an asymmetric pumping by showing that collective excitations are created with a definite direction with respect to the condensate. Furthermore, we measure the critical sound speed for polariton superfluids close to equilibrium.Keywords
This publication has 32 references indexed in Scilit:
- Dissipationless Flow and Sharp Threshold of a Polariton Condensate with Long LifetimePhysical Review X, 2013
- Probing the excitation spectrum of polariton condensatesPhysical Review B, 2009
- Observation of Long-Lived Polariton States in Semiconductor Microcavities across the Parametric ThresholdPhysical Review Letters, 2009
- Goldstone mode of optical parametric oscillators in planar semiconductor microcavities in the strong-coupling regimePhysical Review A, 2007
- Excitations in a Nonequilibrium Bose-Einstein Condensate of Exciton PolaritonsPhysical Review Letters, 2007
- Bose–Einstein condensation of exciton polaritonsNature, 2006
- Condensation kinetics of microcavity polaritons with scattering by phonons and polaritonsPhysical Review B, 2005
- Polariton Condensation with Localized Excitons and Propagating PhotonsPhysical Review Letters, 2004
- Collective Excitations of a Bose-Einstein Condensate in a Dilute GasPhysical Review Letters, 1996
- Observation of Bose-Einstein Condensation in a Dilute Atomic VaporScience, 1995