Giant Effective g-factor Due to Spin Bifurcations in Polariton Condensates

We predict giant susceptibility of spin-bifurcating polariton condensates to externally applied permanent magnetic field. In the presence of spin-anisotropic polariton-polariton interactions, the condensate spontaneously takes an elliptically polarised state, whose perturbation dynamics can be interpreted in terms of the presence of strong effective magnetic field significantly surpassing the external one. Surprisingly, this behaviour of the addressed strongly out-of-equilibrium system in the vicinity of a critical point exhibits intriguing analogy with the second-order phase transition. The predicted field-enhancement effect can be utilized for creation of topologically nontrivial states of Bogoliubov’s excitations existing on top of the polariton condensate.