Tunneling valley Hall effects in monolayer junctions
Phys. Rev. B 114, 045427 – Published 23 July, 2026
DOI: https://doi.org/10.1103/fnmp-rtjx
Abstract
The tunneling valley Hall effect (TVHE) provides high-efficiency conversion from charge to valley, which is crucial to valleytronic devices. Recently, TVHE in two-dimensional junctions has attracted increasing attention. Here, we comprehensively study the TVHE and other tunneling Hall effects in monolayer (TMS) junctions. Monolayer TMS, a representative two-dimensional transition-metal dichalcogenide, hosts gapped and tilted Dirac fermions with spin splitting tunable by an out-of-plane electric field. The tunneling Hall effects for valley and other degrees of freedom reflect the evolution of the unique electronic structure featured by the reversible spin splitting and the topological transition. For the monolayer TMS at zero electric field, the intrinsic valley Hall effect is absent due to the opposite spin Berry curvature in each valley, which makes the TVHE the dominant valley Hall mechanism for valleytronic applications. We further demonstrate the resonant enhancement of TVHE through the transmission pattern and show the electrically tunable high conversion ratio. For the monolayer TMS at nonzero electric field, the TVHE is closely related to the tunneling spin Hall effect due to the valley-spin locking, whose sign and magnitude changes can be used to distinguish the direction of the spin splitting and to provide an indirect signature for the topological transition, respectively. For the tunneling charge Hall effect, a universal conversion ratio is analytically derived and numerically confirmed. This study provides a comprehensive understanding of tunneling Hall effects in monolayer TMS junctions and provides an opportunity for two-dimensional transition-metal dichalcogenides in valleytronics and spintronics.
