Controlling exciton many-body states by the electric-field effect in monolayer MoS_{2}

oleh: J. Klein, A. Hötger, M. Florian, A. Steinhoff, A. Delhomme, T. Taniguchi, K. Watanabe, F. Jahnke, A. W. Holleitner, M. Potemski, C. Faugeras, J. J. Finley, A. V. Stier

Format: Article
Diterbitkan: American Physical Society 2021-04-01

Deskripsi

We report magneto-optical spectroscopy of gated monolayer MoS_{2} in high magnetic fields up to 28T and obtain new insights on the many-body interaction of neutral and charged excitons with the resident charges of distinct spin and valley texture. For neutral excitons at low electron doping, we observe a nonlinear valley Zeeman shift due to dipolar spin-interactions that depends sensitively on the local carrier concentration. As the Fermi energy increases to dominate over the other relevant energy scales in the system, the magneto-optical response depends on the occupation of the fully spin-polarized Landau levels (LL) in both K/K^{′} valleys. This manifests itself in a many-body state. Our experiments demonstrate that the exciton in monolayer semiconductors is only a single particle boson close to charge neutrality. We find that away from charge neutrality it smoothly transitions into polaronic states with a distinct spin-valley flavor that is defined by the LL quantized spin and valley texture.