Drag and critical velocities in a nonresonantly pumped trapped polariton condensate with a rotating defect

•We model the nonlinear dynamics of a polariton fluid under a non-resonant excitation.•Based on the generalized Gross–Pitaevskii equation, the drag force is numerically calculated in the presence of a rotating defect.•The numerical results exhibit different dynamical regimes depending on the linear velocity of the rotating defect.•The critical velocity can be defined through the significant increase of drag force and the onset of turbulent fringes.

We model the superfluid properties of a trapped exciton–polariton condensate under non-resonant excitation subjected to a rotating defect. With increasing the linear velocity of rotating defect, the density modulation can be classified into superfluid-like regime, parabolic-like regime, Cherenkov regime and over-Cherenkov regime. The threshold-like behavior of drag force and the onset of turbulent fringes can define the critical velocity for the superfluidity. Based on the perturbative drag force in the Bogoliubov-type analysis, the rigid modes with gapped excitation spectrum have higher critical velocity than that of the soft modes.