Abstract: 

The talk is devoted to the dynamics of polariton condensates in the rotating complex potentials created by incoherent pumps. By numerical simulation we demonstrate that the rotation of the pump defines the direction of polariton flow. An interesting fact is that the direction of the polariton propagation depends not only on the sign but also on the absolute value of the angular velocity of the pump. To explain this phenomenon a simple perturbation theory is developed and compared against the numerical results. The theory is based on the assumption that the rotating non-symmetric part of the potential can be treated as a small perturbation. It is shown that the formation of the stationary polariton state can then be understood in terms of competition of different eigenmodes of the unperturbed problem. In the scalar case the typical scenario is that the fastest growing linear mode suppresses the other excitations and thus predetermines the structure of the stationary polariton state. The results can be generalized for the vector problem accounting for the polarization degree of freedom. In this case the stationary oscillating states being combinations of two coexisting eigenmodes can be realized easily.

Bio:

Alexey Yulin graduated from the Institute of Applied Physics of Russian Academy of Science, Russia, in 1998 with a PhD degree in Physics, followed by research positions in the Strathclyde University, University of Bath and University of Bristol, UK, and Universidade de Lisboa, Portugal. Since 2014 he is a Leading Research Fellow, Physics Department, Faculty of Physics and Engineering, ITMO University, Saint Petersburg, Russia. In 2020 obtained Dr. Sc. degree (habilitation) in ITMO. Alexey's research interests include nonlinear dynamics of distributed and discrete systems; light-matter interactions,  nonlinear optical and matter waves; computational and analytical methods of the analysis of these systems; propagation of pulses and continuous waves; formation and dynamics of patterns and cavity solitons.