Abstract

The common wisdom tells us that the drag effect is incompatible with superfluidity. A superfluid is characterized by zero viscosity, hence it cannot be dragged. The question we would like discuss here is: does it apply to polariton superfluids as well? The theoretical work by Berman, Kezerashvili and Lozovik offers a negative answer to this question [1]. The authors of Ref. [1] propose the disappearance of drag as a smoking gun for the superfluid transition in an exciton-polariton liquid. This conclusion is challenged by the recent experimental work [2], where the propagation of a polariton superfluid in the presence of an electric current is studied. I will discuss several scenarios that may lead to a (pseudo) drag of a superfluid by an electric current and vice versa. I will show that the most likely mechanism is linked to the driven-dissipative nature of polariton superfluids that brings an interesting new physics which cannot be encountered in a superfluid liquid Helium.

References

O. Berman, R.Ya. Kezerashvili and Yu.E. Lozovik, Drag Effect in a System of Electrons and Polaritons, Phys. Rev. B 82, 125307 (2010).
D.M. Myers, B. Ozden, J. Beaumariage, D.W. Snoke, L.N. Pfeiffer, and K. West, Pushing Photons with Electrons: Observation of the Polariton Drag Effect, arXiv: 1808.07866v1