%0 Journal Article
%T Imaging of pure spin-valley diffusion current in WS 2-WSe 2 heterostructures
%J -
%D 2018
%R 10.1126/science.aao3503
%X Transition metal dichalcogenide (TMDC) materials are promising for spintronic and valleytronic applications because valley-polarized excitations can be generated and manipulated with circularly polarized photons and the valley and spin degrees of freedom are locked by strong spin-orbital interactions. In this study we demonstrate efficient generation of a pure and locked spin-valley diffusion current in tungsten disulfide (WS2)¨Ctungsten diselenide (WSe2) heterostructures without any driving electric field. We imaged the propagation of valley current in real time and space by pump-probe spectroscopy. The valley current in the heterostructures can live for more than 20 microseconds and propagate over 20 micrometers; both the lifetime and the diffusion length can be controlled through electrostatic gating. The high-efficiency and electric-field¨Cfree generation of a locked spin-valley current in TMDC heterostructures holds promise for applications in spin and valley devices
%U http://science.sciencemag.org/content/360/6391/893