Gate controlled spin-valley locking of resident carriers in WSe2 monolayers

Abstract

Using time-resolved Kerr rotation, we measure the spin/valley dynamics of resident electrons and holes in single charge-tunable monolayers of the archetypal transition-metal dichalcogenide (TMD) semiconductor WSe2. In the n-type regime, we observe long (70 ns) polarization relaxation of electrons that is sensitive to in-plane magnetic fields $B_y$, indicating spin relaxation. In marked contrast, extraordinarily long (2 microsecond) polarization relaxation of holes is revealed in the p-type regime, that is unaffected by $B_y$, directly confirming long-standing expectations of strong spin-valley locking of holes in the valence band of monolayer TMDs. Supported by continuous-wave Kerr spectroscopy and Hanle measurements, these studies provide a unified picture of carrier polarization dynamics in monolayer TMDs, which can guide design principles for future valleytronic devices.

arXiv comment5 pages, 3 figures

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Cited by in corpus (50)

• Excitons in atomically thin transition metal dichalcogenides
• Van der Waals heterostructures for spintronics and opto-spintronics
• Two-dimensional semiconductors in the regime of strong light-matter coupling
• First-principles calculations of charge carrier mobility and conductivity in bulk semiconductors and two-dimensional materials
• Enhanced Light-Matter Interaction in Two-Dimensional Transition Metal Dichalcogenides
• Microsecond Valley Lifetime of Defect-Bound Excitons in Monolayer WSe${}_2$
• Defect-induced modification of low-lying excitons and valley selectivity in monolayer transition metal dichalcogenides
• Control of the Exciton Radiative Lifetime in van der Waals Heterostructures
• Guide to optical spectroscopy of layered semiconductors
• Long valley lifetime of dark excitons in single-layer WSe2
• Imaging Spin Dynamics in Monolayer WS2 by Time-Resolved Kerr Rotation Microscopy
• Optical control of a single spin-valley in charged WSe${}_2$ quantum dots
• Magnetooptics of layered two-dimensional semiconductors and heterostructures: progress and prospects
• Valley relaxation of resident electrons and holes in a monolayer semiconductor: Dependence on carrier density and the role of substrate-induced disorder
• Unveiling valley lifetimes of free charge carriers in monolayer WSe${}_2$
• Valley-selective optical Stark effect probed by Kerr rotation
• Momentum-Resolved Exciton Coupling and Valley Polarization Dynamics in Monolayer WS${}_2$
• Spin States Protected from Intrinsic Electron-Phonon-Coupling Reaching 100 ns Lifetime at Room Temperature in MoSe${}_2$
• Gate-defined, Accumulation-mode Quantum Dots in Monolayer and Bilayer WSe${}_2$
• Spectrally narrow exciton luminescence from monolayer MoS2 exfoliated onto epitaxially grown hexagonal BN
• Spin/valley coupled dynamics of electrons and holes at the ${\text{MoS}}_2-{\text{MoSe}}_2$ interface
• Ab initio Ultrafast Spin Dynamics in Solids
• Detection of thermodynamic "valley noise" in monolayer semiconductors: access to intrinsic valley relaxation timescales
• Spin Manipulation by Giant Valley-Zeeman Spin-Orbit Field in Atom-Thick WSe2
• Vibrational dichroism of chiral valley phonons
• Giant Spin Lifetime Anisotropy and Spin-Valley Locking in Silicene and Germanene from First-Principles Density-Matrix Dynamics
• Wigner Crystals in Two-Dimensional Transition-Metal Dichalcogenides: Spin Physics and Readout
• Intervalley Polaron in Atomically Thin Transition Metal Dichalcogenides
• Twist-angle evolution of the intervalley-coherent antiferromagnet in twisted WSe${}_2$
• Spin-valley dynamics in alloy-based transition metal dichalcogenide heterobilayers
• Optical detection of long electron spin transport lengths in a monolayer semiconductor
• The impact of valley profile on the mobility and Kerr rotation of transition metal dichalcogenides
• Topological Ising pairing states in monolayer and trilayer TaS${}_2$
• Spin-valley relaxation dynamics of Landau-quantized electrons in MoSe${}_2$ monolayer
• Third-order Optical Nonlinearity in Two-dimensional Transition Metal Dichalcogenides
• Magnetically tunable exciton valley coherence in monolayer WS${}_2$ mediated by the electron-hole exchange and exciton-phonon interactions
• Layer-dependent optically-induced spin polarization in InSe
• Phonon-limited valley life times in single-particle bilayer graphene quantum dots
• Dynamic Valley Polarization in Moire Quantum Dots
• Rapid spin depolarization in the layered 2D Ruddlesden Popper perovskite (BA)(MA)PbI
• Spin relaxation of localized electrons in monolayer MoSe${}_2$: importance of random effective magnetic fields
• Hydrogenic Spin-Valley states of the Bromine donor in 2H-MoTe${}_2$
• Exchange-enhanced spin-orbit splitting and its density dependence for electrons in monolayer transition metal dichalcogenides
• Spin/Valley pumping of resident electrons in WSe2 and WS2 monolayers
• Theory of field-modulated spin-valley-orbital pseudospin physics
• Valley polarization fluctuations, bistability, and switching in two-dimensional semiconductors
• Valley Gapless Semiconductor: Models and Applications
• Spin and Magnetism in 2D Materials
• Two-color Kerr microscopy of two-dimensional materials with sub-picosecond time resolution
• Hyperfine interaction in atomically thin transition metal dichalcogenides