Phase dislocations in the 2D scattering of microcavity polaritons

The superfluidity of polaritonic condensates has been experimentally proven via the scattering of a flow of polaritons by a localized impurity [1, 2]. The observation of so-called oblique solitons in the wake of the obstacle has been considered as a confirmation of the phenomena. This analysis has been challenged in Ref. [3] where similar experimental results have been interpreted quite differently.
In this talk, I will review the linear and non-linear theory of 2D scattering by an obstacle, propose to observe specific phenomena new in the field of microcavity polariton, and present a criterion for identifying nonlinear structures in these systems.

[1] A. Amo et al., Science 332, 1167 (2011).
[2] G. Grosso et al., Phys. Rev. Lett. 107, 245301 (2011).
[3] P. Cilibrizzi et al., Phys. Rev. Lett. 113, 103901 (2014).