Room-temperature superfluidity in a polariton condensate

TL;DR

This paper demonstrates room-temperature superfluidity in an organic microcavity supporting Frenkel exciton-polaritons, enabling new quantum fluid studies and robust polariton devices at ambient conditions.

Contribution

It reports the first observation of superfluid flow in a polariton condensate at room temperature, overcoming previous temperature limitations.

Findings

Superfluid transition observed at room temperature in organic microcavity.

Stable Frenkel exciton-polaritons support superfluidity.

Potential for room-temperature quantum hydrodynamics and devices.

Abstract

Superfluidity---the suppression of scattering in a quantum fluid at velocities below a critical value---is one of the most striking manifestations of the collective behaviour typical of Bose-Einstein condensates. This phenomenon, akin to superconductivity in metals, has until now only been observed at prohibitively low cryogenic temperatures. For atoms, this limit is imposed by the small thermal de Broglie wavelength, which is inversely related to the particle mass. Even in the case of ultralight quasiparticles such as exciton-polaritons, superfluidity has only been demonstrated at liquid helium temperatures. In this case, the limit is not imposed by the mass, but instead by the small exciton binding energy of Wannier-Mott excitons, which places the upper temperature limit. Here we demonstrate a transition from normal to superfluid flow in an organic microcavity supporting stable Frenkel exciton-polaritons at room temperature. This result paves the way not only to table-top studies of quantum hydrodynamics, but also to room-temperature polariton devices that can be robustly protected from scattering.