An acoustic black hole in a stationary hydrodynamic flow of microcavity polaritons

TL;DR

This paper demonstrates superfluid hydrodynamic effects, including an acoustic horizon, in a polariton fluid flowing in a microcavity, with potential implications for observing Hawking radiation.

Contribution

It provides the first experimental observation of an acoustic black hole in a polariton fluid, supported by theoretical modeling.

Findings

Superfluid propagation effects observed at high excitation power

Formation of a sharp acoustic horizon at the defect

Theoretical calculations match experimental results

Abstract

We report an experimental study of superfluid hydrodynamic effects in a one-dimensional polariton fluid flowing along a laterally patterned semiconductor microcavity and hitting a micron-sized engineered defect. At high excitation power, superfluid propagation effects are observed in the polariton dynamics, in particular, a sharp acoustic horizon is formed at the defect position, separating regions of sub- and super-sonic flow. Our experimental findings are quantitatively reproduced by theoretical calculations based on a generalized Gross-Pitaevskii equation. Promising perspectives to observe Hawking radiation via photon correlation measurements are illustrated.