Speaker
Description
Monolayer transition metal dichalcogenides have emerged as key materials for investigating the interplay between spin and valley degrees of freedom. The strong spin-orbit interaction and the lack of inversion symmetry in these materials result in a spin-valley locking, in which carriers in the K and K’ valleys possess opposite spin polarization. This effect is particularly pronounced for holes due to the large spin-orbit splitting of the valence band.
In this talk, I will highlight how spin-valley locking shapes magnetotransport in monolayer tungsten diselenide confined to different dimensions through electrostatic gating.
In two dimensions, we report magnetotransport measurements in perpendicular magnetic fields up to 8 T, revealing a Landau fan diagram consistent with fully spin-polarized hole transport at low filling factors. At higher carrier densities, the Landau fan exhibits an unconventional alternating resistance pattern.
We further demonstrate electrostatic confinement of monolayer tungsten diselenide into one dimension. In this regime, spin-valley locking combined with strong hole-hole interactions leads to a ferromagnetic ground state, resulting in spin- and valley-polarized transport even in the absence of an external magnetic field. The persistence of this polarized configuration can be tuned using a global back-gate. Finally, we will present measurements in the zero-dimensional confinement regime.
Together, these results establish monolayer tungsten diselenide as a versatile platform for engineering and controlling spin- and valley-polarized states, opening opportunities for realizing quantum circuits in 2D semiconductors
| Keyword-1 | 2D Materials |
|---|---|
| Keyword-2 | Low temperature transport |
| Keyword-3 | Gate-defined structures |