Anomalous sign of the polaron effect for excitons interacting with an incompressible fluid
Apal'kov V. M., Rashba E. I.
A dispersion relation is derived for a magnetoexciton interacting with a 2D incompressible fluid. In an asymmetric system, the shift of the exciton level caused by this interaction has the sign opposite that of the ordinary polaron shift. When the asymmetry parameter reaches a critical value, the absolute minimum of the exciton spectrum is displaced to a circle. This effect results in an abrupt change in the properties of the emission spectrum. A model for the new ground state is proposed.