Magnetooptics of Exciton Rydberg States in a Monolayer Semiconductor

A V Stier; N P Wilson; K A Velizhanin; J Kono; X Xu; S A Crooker

doi:10.1103/PhysRevLett.120.057405

Magnetooptics of Exciton Rydberg States in a Monolayer Semiconductor

Phys Rev Lett. 2018 Feb 2;120(5):057405. doi: 10.1103/PhysRevLett.120.057405.

Authors

A V Stier¹, N P Wilson², K A Velizhanin³, J Kono⁴, X Xu², S A Crooker¹

Affiliations

¹ National High Magnetic Field Laboratory, Los Alamos, New Mexico 87545, USA.
² Department of Physics, University of Washington, Seattle, Washington 98195, USA.
³ Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
⁴ Departments of Electrical and Computer Engineering, Physics and Astronomy, and Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, USA.

PMID: 29481196
DOI: 10.1103/PhysRevLett.120.057405

Abstract

We report 65 T magnetoabsorption spectroscopy of exciton Rydberg states in the archetypal monolayer semiconductor WSe_{2}. The strongly field-dependent and distinct energy shifts of the 2s, 3s, and 4s excited neutral excitons permits their unambiguous identification and allows for quantitative comparison with leading theoretical models. Both the sizes (via low-field diamagnetic shifts) and the energies of the ns exciton states agree remarkably well with detailed numerical simulations using the nonhydrogenic screened Keldysh potential for 2D semiconductors. Moreover, at the highest magnetic fields, the nearly linear diamagnetic shifts of the weakly bound 3s and 4s excitons provide a direct experimental measure of the exciton's reduced mass m_{r}=0.20±0.01m_{0}.