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.