Valley Properties and Dynamics in 2D Transition Metal Dichalcogenides: Prospects for Valleytronic Applications.

Two-dimensional (2D) transition metal dichalcogenides (TMDs) have emerged as a unique class of materials that host robust valley degrees of freedom. This opens exciting possibilities for valleytronic applications where information is encoded in the electronic valleys of momentum space. The inherent inversion symmetry breaking and strong spin-orbit coupling in monolayer TMDs give rise to valley-selective optical selection rules and spin-valley locking, making them ideal candidates for manipulating valley pseudospins in next-generation quantum devices. This Perspective highlights the fundamental valley physics focusing on valley dynamics in 2D TMDs, including valley polarization and coherence, and reviews recent experimental advancements in valley control using optical, electrical, and magnetic means. We further discuss emerging directions such as valley-based quantum computing, coherent valley manipulation at ultrafast time scales, and hybrid valleytronic architectures that integrate TMDs with other quantum materials. The Perspective outlines key challenges, including valley depolarization mechanisms, material quality, and scalability, and proposes strategic approaches to overcome these hurdles. As valleytronics research transitions from proof-of-concept studies toward real-world technologies, 2D TMDs stand at the forefront of a promising frontier in quantum information science.