Monolayer transition metal dichalcogenides having giant valley-polarized rydberg excitons revealed by magneto-photocurrent spectroscopy

A system for revealing excitons in a transition metal dichalcogenides comprising:

• a broadband light source configured to emit excitation photon energy;
• a tunable filter configured to filter the excitation photon energy to a predetermined wavelength bandwidth;
• a linear polarizer configured to linearly polarize the filtered excitation photon energy;
• and
• a quarter waveplate configured to convert the linearly polarized excitation photon energy into circularly polarized excitation photon energy to excite the transition metal dichalcogenides.

A method of revealing excitons in a transition metal dichalcogenides comprising:

• providing the transition metal dichalcogenides, the transition metal dichalcogenides comprising:
• a substrate;
• at least one layer of boron nitride;
• a tungsten diselenide monolayer positioned such that the at least one layer of boron nitride at least partially encapsulates the tungsten diselenide monolayer;
• and
• a plurality of electrodes;
• exposing the transition metal dichalcogenides to an external magnetic field;
• emitting excitation photon energy from a broadband light source;
• filtering, via a tunable filter, the excitation photon energy to a predetermined wavelength bandwidth;
• linearly polarizing, via a linear polarizer, the filtered excitation photon energy;
• converting, via a quarter waveplate, the linearly polarized excitation photon energy to circularly polarized excitation photon energy;
• and
• focusing, via a focusing element, the circularly polarized excitation photon energy onto the tungsten diselenide monolayer of the transition metal dichalcogenides.