Valley-spin polarization at zero magnetic field induced by strong hole-hole interactions in monolayer WSe₂

Monolayer transition metal dichalcogenides have emerged as key materials for investigating the intricate relationship between spin and valley degrees of freedom. The pronounced spin-orbit interaction and the lack of inversion symmetry in these materials result in a spin-valley locking effect, an effect that is particularly pronounced for holes due to the larger spin-orbit gap in the valence band.



In this presentation, we demonstrate that by confining a monolayer of tungsten diselenide to one dimension via electrostatic confinement, the combination of the spin-valley locking mechanism and strong hole-hole interactions lead to a ferromagnetic state in which hole transport through the one-dimensional system is valley-spin polarized, even in the absence of an external magnetic field. Furthermore, we demonstrate that the stability of this valley-spin polarized configuration can be tuned by a global back-gate. Finally, we present transport data taken at high magnetic field which reveals an unusual subband filling pattern that is explained by a subband freezing mechanism.