Magnetic Field Induced Inter‐Valley Trion Dynamics in Monolayer 2D Semiconductor

Abstract The valley polarization dynamics of excitonic states (excitons and trions) in monolayer (1L)‐MoSe 2 under strong magnetic field are investigated. The experimentally observed magnetic‐field‐induced valley polarizations of trions (excitons) are analyzed by the rate equation model. It is found that the magnetic‐field‐induced valley polarizations are attributed to the asymmetric valley scattering of trions from K+ to K− valley and vice versa due to the degeneracy lifting of K+ and K− valleys by valley Zeeman effect under magnetic field. Moreover, the feeding of the valley‐polarized excitons for trions formation and longer inter‐valley scattering time reaching to a few nanoseconds at 10 K contribute to the larger valley polarization of trions than that of excitons in 1L‐MoSe 2 .