Spin/Valley pumping of resident electrons in WSe2 and WS2 monolayers
arXiv:2105.04861 · doi:10.1038/s41467-021-25747-5
Abstract
Monolayers of transition metal dichalcogenides are ideal materials to control both spin and valley degrees of freedom either electrically or optically. Nevertheless, optical excitation mostly generates excitons species with inherently short lifetime and spin/valley relaxation time. Here we demonstrate a very efficient spin/valley optical pumping of resident electrons in n-doped WSe2 and WS2 monolayers. We observe that, using a continuous wave laser and appropriate doping and excitation densities, negative trion doublet lines exhibit circular polarization of opposite sign and the photoluminescence intensity of the triplet trion is more than four times larger with circular excitation than with linear excitation. We interpret our results as a consequence of a large dynamic polarization of resident electrons using circular light.
References in corpus (38)
- Atomically thin MoS2: A new direct-gap semiconductor
- Coupled spin and valley physics in monolayers of MoS2 and other group-VI dichalcogenides
- Control of valley polarization in monolayer MoS2 by optical helicity
- Valley polarization in MoS2 monolayers by optical pumping
- MoS_2 as an ideal material for valleytronics: valley-selective circular dichroism and valley Hall effect
- Excitons in atomically thin transition metal dichalcogenides
- Measurement of the optical dielectric function of transition metal dichalcogenide monolayers: MoS2, MoSe2, WS2 and WSe2
- k.p theory for two-dimensional transition metal dichalcogenide semiconductors
- Exciton physics and device application of two-dimensional transition metal dichalcogenide semiconductors
- Excitonic linewidth approaching the homogeneous limit in MoS2 based van der Waals heterostructures : accessing spin-valley dynamics
- Fermi polaron-polaritons in charge-tunable atomically thin semiconductors
- Exciton Radiative Lifetime in Transition Metal Dichalcogenide Monolayers
- Magnetic brightening and control of dark excitons in monolayer WSe2
- Robust optical emission polarization in MoS2 monolayers through selective valley excitation
- In-plane Propagation of Light in Transition Metal Dichalcogenide Monolayers: Optical Selection Rules
- Probing dark excitons in atomically thin semiconductors via near-field coupling to surface plasmon polaritons
- Valley depolarization due to inter- and intra-valley electron-hole exchange interactions in monolayer MoS
- Charged excitons in monolayer WSe: experiment and theory
- Exciton Valley Dynamics probed by Kerr Rotation in WSe2 Monolayers
- Transport Theory of Monolayer Transition-Metal Dichalcogenides through Symmetry
- Trion Formation Dynamics in Monolayer Transition Metal Dichalcogenides
- Exciton Dynamics in Monolayer Transition Metal Dichalcogenides
- Valley Phonons and Exciton Complexes in a Monolayer Semiconductor
- Polarization analysis of excitons in monolayer and bilayer transition-metal dichalcogenides
- Electroluminescence from multi-particle exciton complexes in transition metal dichalcogenide semiconductors
- Microsecond dark-exciton valley polarization memory in 2D heterostructures
- Gate controlled spin-valley locking of resident carriers in WSe2 monolayers
- Gate tunable dark trions in monolayer WSe
- Optical properties of charged excitons in two-dimensional semiconductors
- Giant paramagnetism induced valley polarization of electrons in charge-tunable monolayer MoSe2
- Direct Observation of Gate Tunable Dark Trions in Monolayer WSe2
- Singlet and triplet trions in WS monolayer encapsulated in hexagonal boron nitride
- Long valley lifetime of free carriers in monolayer WSe2
- Measurement of Conduction and Valence Bands g-factors in a Transition Metal Dichalcogenide Monolayer
- 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
- Detection of thermodynamic "valley noise" in monolayer semiconductors: access to intrinsic valley relaxation timescales
- Controlling valley splitting and Polarization of dark- and bi-excitons in monolayer WS by a tilted magnetic field
Cited by in corpus (3)
- Relaxation and darkening of excitonic complexes in electrostatically-doped monolayer semiconductors: Roles of exciton-electron and trion-electron interactions
- Many-body exciton and inter-valley correlations in heavily electron-doped WSe monolayers
- Optical detection of long electron spin transport lengths in a monolayer semiconductor