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Coherently driven microcavity-polaritons and the question of superfluidity.

ABSTRACT: Due to their driven-dissipative nature, photonic quantum fluids present new challenges in understanding superfluidity. Some associated effects have been observed, and notably the report of nearly dissipationless flow for coherently driven microcavity-polaritons was taken as a smoking gun for superflow. Here, we show that the superfluid response-the difference between responses to longitudinal and transverse forces-is zero for coherently driven polaritons. This is a consequence of the gapped excitation spectrum caused by external phase locking. Furthermore, while a normal component exists at finite pump momentum, the remainder forms a rigid state that is unresponsive to either longitudinal or transverse perturbations. Interestingly, the total response almost vanishes when the real part of the excitation spectrum has a linear dispersion, which was the regime investigated experimentally. This suggests that the observed suppression of scattering should be interpreted as a sign of this new rigid state and not a superfluid.

SUBMITTER: Juggins RT

PROVIDER: S-EPMC6170389 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature

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Coherently driven microcavity-polaritons and the question of superfluidity.

Juggins R T RT Keeling J J Szymańska M H MH

Nature communications 20181003 1

Due to their driven-dissipative nature, photonic quantum fluids present new challenges in understanding superfluidity. Some associated effects have been observed, and notably the report of nearly dissipationless flow for coherently driven microcavity-polaritons was taken as a smoking gun for superflow. Here, we show that the superfluid response-the difference between responses to longitudinal and transverse forces-is zero for coherently driven polaritons. This is a consequence of the gapped exci ...[more]

PMID: 30282978

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