Magneto-photoluminescence of exciton Rydberg states in monolayer WSe$_2$

TL;DR

This study investigates the magneto-photoluminescence of exciton Rydberg states in monolayer WSe₂, revealing their Zeeman and diamagnetic behaviors, and deducing key exciton properties under high magnetic fields.

Contribution

First measurement of photoluminescence from multiple exciton Rydberg states in monolayer WSe₂ under strong magnetic fields, providing new insights into their optical and magnetic properties.

Findings

Zeeman shifts are similar across Rydberg states.

Distinct diamagnetic shifts allow determination of exciton radii.

Results align with theoretical models and prior experiments.

Abstract

Monolayer WSe$_2$ hosts a series of exciton Rydberg states denoted by the principal quantum number n = 1, 2, 3, etc. While most research focuses on their absorption properties, their optical emission is also important but much less studied. Here we measure the photoluminescence from the 1s - 5s exciton Rydberg states in ultraclean monolayer WSe$_2$ encapsulated by boron nitride under magnetic fields from -31 T to 31 T. The exciton Rydberg states exhibit similar Zeeman shifts but distinct diamagnetic shifts from each other. From their luminescence spectra, Zeeman and diamagnetic shifts, we deduce the binding energies, g-factors and radii of the 1s - 4s exciton states. Our results are consistent with theoretical predictions and results from prior magneto-reflection experiments.