Electrical control of valley dynamics in proximity-coupled TMD-based van der Waals heterostructures

• Applicant: Dr. Bernd Beschoten
• Subject Area: Experimental Condensed Matter Physics
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 576172609

The main goal of this project is to create valley polarizations of free charge carriers in van der Waals heterostructures based on transition metal dichalcogenides (TMDs) by either proximity exchange coupling to a 2D magnet, by interlayer charge transfer, or by pulsed electric fields. We propose to combine time-resolved optical and electrical measurement techniques to study the underlying polarization mechanisms and valley dynamics, which will help to explore novel pathways to use the valley information in potential valleytronic devices. In particular, our proposal aims to find answers to the following main questions: 1.) Can the proximity exchange coupling of a 2D magnet create a net valley polarization of free charge carriers in the TMD and what is its lifetime? 2.) Is it possible to use gate voltage pulses to electrically generate valley currents in proximity exchange-coupled TMDs on ultrafast time-scales? 3.) Can long-lived interlayer valley excitons in TMD-based heterobilayers transfer their valley information to the free conduction and valence band states of the host layers by the use of electric field pulses?

• DFG Programme: Research Grants
• Co-Investigator: Professor Dr. Christoph Stampfer