Valleytronic quantum devices

TMDs have strong spin-orbit coupling and result in two equivalent K valleys but with opposite spin characteristics. By breaking time-reversal symmetry, the two valleys can become inequivalent in population or in energy and can be used for storing information. Interlayer excitons in these heterostructures can have long lifetimes and can carry the spin or valley information, providing an electrically controllable system. We can design quantum devices to manipulate the valley and spin properties by controlling the excitons with current, electrostatic gates, and magnetic fields.

Another way to take advantage of the spin-orbit coupling in the TMDs is to interface them with magnetic substrates. With a family of magnetic thin-films with various magnetic properties, the valley and spin states in the TMD can be highly controlled and manipulated by changing or tuning the substrate. The convenient and powerful ability to read-out the spin and magnetic states of these materials using light gives a unique platform for both quantum information applications and fundamental studies.