Valley Polarization Modulation in Transition Metal Dichalcogenides via Chiral Interfaces

Valleytronics is an emerging concept in condensed matter physics that exploits the valley degree of freedom of electrons in certain semiconductors as an information carrier, analogous to the use of charge in electronics and spin in spintronics. Two-dimensional transition metal dichalcogenides (TMDs) provide an ideal platform for valleytronics because their electronic band structures contain distinct energy valleys that can be selectively addressed by circularly polarized light. However, achieving strong and controllable valley polarization, especially at room temperature, remains a major challenge. Recent studies suggest that chiral materials can interact with electron spin through the chiral- induced spin selectivity (CISS) effect, offering a new route to manipulate spin and valley degrees of freedom in two-dimensional systems. This project aims to explore the control of valley polarization in TMDs using chiral interfaces (Figure 1). By integrating chiral powders or chiral polymer thin films with monolayer TMDs, we will investigate how chiral structures influence spin–valley coupling and optical responses. The results will provide new insights into chiral–2D material interactions and may open new opportunities for developing valleytronic devices operating at room temperature.