We investigate exciton-polariton condensation under magnetic field in a single high-quality semiconductor micropillar cavity. We observe successive polariton condensation of each spin component for two distinct threshold powers. Pronounced and non-monotonous variations of both the Zeeman splitting and the circular polarization of the emission are measured across these two condensation thresholds. This unexpected behavior deeply deviates from the so-called spin Meissner effect predicted for a fully thermalized system. Our measurements can be understood in a kinetic approach taking into account spin-anisotropic interactions within the entire system: the polariton condensate and the cloud of uncondensed excitons.
@article{arxiv.1409.5112,
title = {Driven-dissipative confined polariton condensate under magnetic field},
author = {C. Sturm and D. Solnyshkov and O. Krebs and A. Lemaître and I. Sagnes and E. Galopin and A. Amo and G. Malpuech and J. Bloch},
journal= {arXiv preprint arXiv:1409.5112},
year = {2014}
}