Fig. 1.

Dark exciton PL splitting in magnetic field. a Schematic representation of BN encapsulated monolayer WSe₂ with graphene contact and top gate electrodes. b PL spectra of the device in (a) at 4.2 K without the application of the top gate voltage, with no magnetic field (black) and with 6 T out-of-plane magnetic field (magenta) applied. c Integrated PL intensity of WSe₂ as a function of the excitation power for the X₀, X_D and ${\mathrm{X}}_{\mathrm{D}}^{\mathrm{R}}$ PL peaks. d Schematic configurations of exciton and dark-exciton states with the solid and empty dots representing the electron and hole. Blue and orange colors stand for spin-up and spin-down bands, respectively