Dresden 2017 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 34: Two-dimensional materials III (joined session with TT)

HL 34.8: Talk

Tuesday, March 21, 2017, 12:00–12:15, POT 51

Transport measurements in graphene-WSe₂ heterostructures — •Tobias Völkl¹, Tobias Rockinger¹, Martin Drienovsky¹, Kenji Watanabe², Takashi Taniguchi², Dieter Weiss¹, and Jonathan Eroms¹ — ¹Universität Regensburg, Germany — ²National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan

Bringing graphene into proximity to WSe₂ was proposed as a way to induce a high spin orbit coupling strength in graphene, while maintaining the high intrinsic mobility of graphene. We therefore investigated the transport properties of graphene-WSe₂ heterostructures.

Placing graphene onto a WSe₂-flake resulted in mobilities around 10000 cm²/Vs of graphene. Further a weak antilocalization behavior was observed, which indicates a high spin orbit coupling strength induced by the WSe₂.

Higher mobilities around 100000 cm²/Vs were achieved by encapsulation of graphene between WSe₂ and hBN. In these samples no weak antilocalization behavior could be observed. We attribute this to a transition from diffusive to the quasiballistic regime. Also a feature dependent on the sample width arises in the low magnetic field range. We attribute this to a magneto size effect which further indicates quasiballistic behavior.