Magneto-spectroscopy probe of exciton-electron interactions in monolayer MoSe2

Coulomb interaction driven many-body effects are expected to modify significantly the quasiparticles properties in monolayer transition metal dichalcogenides at high carrier densities. Here we report on low temperature magneto- photoluminescence and broadband reflection contrast measurements on high quality monolayer MoSe2 over a wide doping range. A valley g-factor around 4 is measured in the low-density regime, which is consistent with the value deduced from the single particle picture. As the carrier density increases, one can access the strongly interacting regime and observe a pronounced change of the valley magnetic response. The observed strong modification of the valley g-factor in highly doped MoSe2 will be discussed and compared to the previously reported results on WSe2 [1].

[1]. PRL 120, 066402 (2018)