Stochastic spin flips in polariton condensates: nonlinear tuning from GHz to sub-Hz

Abstract

The stability of spin of macroscopic quantum states to intrinsic noise is studied for non-resonantly-pumped optically-trapped polariton condensates. We demonstrate flipping between the two spin-polarised states with >10 ^4 slow-down of the flip rate by tuning the optical pump power. Individual spin flips faster than 50 ps are time resolved using single-shot streak camera imaging. We reproduce our results within a mean-field model accounting for cross-spin scattering between excitons and polaritons, yielding a ratio of cross- to co-spin scattering of ∼0.6, in contrast with previous literature suggestions.

Keywords

• exciton–polariton
• spin dynamics
• non-equilibrium condensate
• driven-dissipative
• chaos