Magnetotransport in heterostructures of transition metal dichalcogenides and graphene

Abstract

We use a van-der-Waals pickup technique to fabricate different heterostructures containing WSe${}_2$(WS${}_2$) and graphene. The heterostructures were structured by plasma etching, contacted by one-dimensional edge contacts and a topgate was deposited. For graphene/WSe${}_2$/SiO${}_2$ samples we observe mobilities of $\sim$12 000 cm${}^2$/Vs. Magnetic field dependent resistance measurements on these samples show a peak in the conductivity at low magnetic field. This dip is attributed to the weak antilocalization (WAL) effect, stemming from spin-orbit coupling. Samples where graphene is encapsulated between WSe${}_2$(WS${}_2$) and hBN show a much higher mobility of up to $\sim$120 000 cm${}^2$/Vs. However, in these samples no WAL peak can be observed. We attribute this to a transition from the diffusive to the quasiballistic regime. At low magnetic field a resistance peak appears, which we ascribe to a size effect, due to boundary scattering. Shubnikov-de Haas oscillations in fully encapsulated samples show all integer filling factors, due to complete lifting of the spin and valley degeneracy.

Revised version, accepted by Phys Rev B

References in corpus (7)

• Spin-Orbit Proximity Effect in Graphene
• Tunneling Spin Injection into Single Layer Graphene (Supplementary Information)
• Tunneling Spin Injection into Single Layer Graphene
• Tunable spin-orbit coupling and symmetry-protected edge states in graphene/WS${}_2$
• Quantum spin Hall states in graphene interacting with WS${}_2$ or WSe${}_2$
• Strong spin-orbit interactions and weak antilocalization in carbon doped p-type GaAs heterostructures
• Boundary Scattering in Ballistic Graphene

Cited by in corpus (8)

• Van der Waals heterostructures for spintronics and opto-spintronics
• Spin-orbit driven band inversion in bilayer graphene by van der Waals proximity effect
• Optimal charge-to-spin conversion in graphene on transition metal dichalcogenides
• Quantum Anomalous Hall Effects in Graphene from Proximity-Induced Uniform and Staggered Spin-Orbit and Exchange Coupling
• Spin-split band hybridization in graphene proximitized with $\alpha$-RuCl${}_3$ nanosheets
• Spin Hall and inverse spin galvanic effects in graphene with strong interfacial spin-orbit coupling: a quasi-classical Green's function approach
• Effect of proximity-induced spin-orbit coupling in graphene mesoscopic billiards
• Proximity spin-orbit coupling in graphene on alloyed transition metal dichalcogenides