Revealed by Magneto-photocurrent Spectroscopy*

Monolayer transition metal dichalcogenides, with their greatly enhanced Coulomb interaction, are an ideal platform to host the Rydberg excitons in two dimensions. Here, we employ helicity-resolved magneto-photocurrent spectroscopy to identify Rydberg exciton states up to 11s in monolayer WSe₂, from which the exciton binding energy and exciton radius can be extracted accurately. Photocurrent spectroscopy of monolayer WSe₂ opens the path to study strong enhanced electron-electron interaction that leads to large nonlinearity such Rydberg exciton blockade, and it can be utilized for quantum information processing and quantum simulation.