Generation and Electric Control of Spin-Coupled Valley Current in WSe2
arXiv:1403.2696 · doi:10.1038/nnano.2014.183
Abstract
The valley degree of freedom in layered transition-metal dichalcogenides (MX2) provides the opportunity to extend functionalities of novel spintronics and valleytronics devices. Due to spin splitting induced by spin-orbital coupling (SOC), the non-equilibrium charge carrier imbalance between two degenerate and inequivalent valleys to realize valley/spin polarization has been successfully demonstrated theoretically and supported by optical experiments. However, the generation of a valley/spin current by the valley polarization in MX2 remains elusive and a great challenge. Here, within an electric-double-layer transistor based on WSe2, we demonstrated a spin-coupled valley photocurrent whose direction and magnitude depend on the degree of circular polarization of the incident radiation and can be further greatly modulated with an external electric field. Such room temperature generation and electric control of valley/spin photocurrent provides a new property of electrons in MX2 systems, thereby enabling new degrees of control for quantum-confined spintronics devices.
21 pages, 5 figures
References in corpus (6)
- Valley polarization in MoS2 monolayers by optical pumping
- Dissipationless Quantum Spin Current at Room Temperature
- Valley filter and valley valve in graphene
- Valley Dependent Optoelectronics from Inversion Symmetry Breaking
- Controlling electron-phonon interactions in graphene at ultra high carrier densities
- Spin-Valley Optical Selection Rule and Strong Circular Dichroism in Silicene
Cited by in corpus (21)
- Pressure induced metallization with absence of structural transition in layered MoSe2
- Probing the spin-polarized electronic band structure in monolayer transition metal dichalcogenides by optical spectroscopy
- Optical detection and manipulation of spontaneous gyrotropic electronic order in a transition-metal dichalcogenide semimetal
- Uncovering edge states and electrical inhomogeneity in MoS2 field-effect transistors
- Nonlinear valley and spin currents from Fermi pocket anisotropy in 2D crystals
- Colossal switchable photocurrents in topological Janus transition metal dichalcogenides
- Symmetries of quantum transport with Rashba spin-orbit: Graphene spintronics
- Spin and Valley Control of Free Carriers in Single-Layer WS
- Optical generation and detection of pure valley current in monolayer transition metal dichalcogenides
- Towards colloidal spintronics through Rashba spin-orbit interaction in lead sulphide nanosheets
- High-frequency nonlinear transport and photogalvanic effects in two-dimensional topological insulators
- Helicity dependent photovoltaic effect in Bi2Se3 under normal incident light
- Switchable enhanced spin photocurrent in Rashba and cubic Dresselhaus ferroelectric semiconductors
- Spin-dependent Refraction at the Atomic Step of Transition-metal Dichalcogenides
- Photoinduced Rashba spin to charge conversion via interfacial unoccupied state
- Photodetection in p-n junctions formed by electrolyte-gated transistors of two-dimensional crystals
- Topological Insulator Metamaterial with Giant Circular Photogalvanic Effect
- Very High Interfacial Thermal Conductance in Fully hBN-Encapsulated MoS2 van der Waals Heterostructure
- Spin and valley polarized one-way Klein tunneling in photonic topological insulators
- Thermal Conductivities and Interfacial Thermal Conductance of 1- to 3-Layer WSe
- Stacked polarimeters with twisted black phosphorus