Nonlocal topological valley transport at large valley Hall angles

Abstract

Berry curvature hot spots in two-dimensional materials with broken inversion symmetry are responsible for the existence of transverse valley currents, which give rise to giant nonlocal dc voltages. Recent experiments in high-quality gapped graphene have highlighted a saturation of the nonlocal resistance as a function of the longitudinal charge resistivity ${\rho }_{\mathrm{c},xx}$, when the system is driven deep into the insulating phase. The origin of this saturation is, to date, unclear. In this work we show that this behavior is fully compatible with bulk topological transport in the regime of large valley Hall angles (VHAs). We demonstrate that, for a fixed value of the valley diffusion length, the dependence of the nonlocal resistance on ${\rho }_{\mathrm{c},xx}$ weakens for increasing VHAs, transitioning from the standard ${\rho }_{\mathrm{c},xx}^3$ power-law to a result that is independent of ${\rho }_{\mathrm{c},xx}$.

5 pages, 3 figures

References in corpus (5)

• The Valley Hall Effect in MoS2 Transistors
• Direct electronic measurement of the spin Hall effect
• Detecting Topological Currents in Graphene Superlattices
• Proximity-induced ferromagnetism in graphene revealed by anomalous Hall effect
• Giant Nonlocality near the Dirac Point in Graphene

Cited by in corpus (7)

• Theory of plasmonic effects in nonlinear optics: the case of graphene
• Viscous magnetoresistance of correlated electron liquids
• Topological Valley Currents in Bilayer Graphene/Hexagonal Boron Nitride Superlattices
• Valley Hall Effect and Nonlocal Transport in Strained Graphene
• Valley current generation using biased bilayer graphene dots
• Topological valley currents via ballistic edge modes in graphene superlattices near the primary Dirac point
• Control of Spin Diffusion and Suppression of the Hanle Effect by the Coexistence of Spin and Valley Hall Effects