title: Valleytronics. The valley Hall effect in MoS₂ transistors.
abstract: Electrons in two-dimensional crystals with a honeycomb lattice structure possess a valley degree of freedom (DOF) in addition to charge and spin. These systems are predicted to exhibit an anomalous Hall effect whose sign depends on the valley index. Here, we report the observation of this so-called valley Hall effect (VHE). Monolayer MoS2 transistors are illuminated with circularly polarized light, which preferentially excites electrons into a specific valley, causing a finite anomalous Hall voltage whose sign is controlled by the helicity of the light. No anomalous Hall effect is observed in bilayer devices, which have crystal inversion symmetry. Our observation of the VHE opens up new possibilities for using the valley DOF as an information carrier in next-generation electronics and optoelectronics.
authors: Kavli Institute at Cornell for Nanoscale Science, Ithaca, NY 14853, USA. Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY 14853, USA. plm23@cornell.edu km627@cornell.edu.
authors: K F
authors: KF
authors: Mak
authors: Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY 14853, USA.
authors: K L
authors: KL
authors: McGill
authors: Kavli Institute at Cornell for Nanoscale Science, Ithaca, NY 14853, USA. Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA.
authors: J
authors: J
authors: Park
authors: Kavli Institute at Cornell for Nanoscale Science, Ithaca, NY 14853, USA. Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY 14853, USA. plm23@cornell.edu km627@cornell.edu.
authors: P L
authors: PL
authors: McEuen