Helicity resolved Raman scattering of MoS2, MoSe2, WS2 and WSe2 atomic layers

Abstract

The two-fold valley degeneracy in two-dimensional (2D) semiconducting transition metal dichalcogenides (TMDCs) (Mo,W)(S,Se)2 is suitable for "valleytronics", the storage and manupulation of information utilizing the valley degree of freedom. The conservation of luminescent photon helicity in these 2D crystal monolayers has been widely regarded as a benchmark indicator for charge carrier valley polarization. Here we perform helicity-resolved Raman scattering of the TMDC atomic layers. In drastic contrast to luminescence, the dominant first-order zone-center Raman bands, including the low energy breathing and shear modes as well as the higher energy optical phonons, are found to either maintain or completely switch the helicity of incident photons. These experimental observations, in addition to providing a useful tool for characterization of TMDC atomic layers, shed new light on the connection between photon helicity and valley polarization.

References in corpus (15)

• Electric Field Effect in Atomically Thin Carbon Films
• Two Dimensional Atomic Crystals
• Anomalous Lattice Vibrations of Single and Few-Layer MoS2
• Valley polarization in MoS2 monolayers by optical pumping
• Two-Dimensional Material Nanophotonics
• The Valley Hall Effect in MoS2 Transistors
• Valley filter and valley valve in graphene
• Tightly bound excitons in monolayer WSe2
• Probing Excitonic Dark States in Single-layer Tungsten Disulfide
• High Mobility WSe2 p- and n-Type Field Effect Transistors Contacted by Highly Doped Graphene for Low-Resistance Contacts
• Layer breathing modes in few-layer graphene
• Second order resonant Raman scattering in single layer tungsten disulfide (WS${}_2$)
• Temperature-activated layer-breathing vibrations in few-layer graphene
• Circular dichroism of magneto-phonon resonance in doped graphene
• Raman scattering from the CaC6 superconductor in the presence of disorder

Cited by in corpus (37)

• Activation of new Raman modes by inversion symmetry breaking in type II Weyl semimetal candidate T'-MoTe2
• Strain-shear coupling in bilayer MoS2
• Stacking-Dependent Interlayer Phonons in 3R and 2H MoS${}_2$
• Superior valley polarization and coherence of 2s excitons in monolayer WSe2
• Recent Progress of Heterostructures Based on Two Dimensional Materials and Wide Bandgap Semiconductors
• Chiral phonons in honeycomb sublattice of layered CoSn-like compounds
• Low-frequency Raman scattering in WSe${}_2$-MoSe${}_2$ heterobilayers: Evidence for atomic reconstruction
• The optical signature of few-layer ReSe${}_2$
• QERaman: An open-source program for calculating resonance Raman spectra based on Quantum ESPRESSO
• Valley Degree of Freedom in Two-Dimensional van der Waals Materials
• Highly Accurate, Reliable and Non-Contaminating Two-Dimensional Material Transfer System
• Chiral valley phonons and flat phonon bands in moiré materials
• Adiabatic dynamics of coupled spins and phonons in magnetic insulators
• Up- and Down-Conversion between Intra- and Inter-Valley Excitons in Waveguide Coupled Monolayer WSe2
• Helicity-selective Raman scattering from in-plane anisotropic α-MoO${}_3$
• Direct Observation of Intravalley Phonon Scattering of 2s Excitons in MoSe${}_2$ and WSe${}_2$ Monolayers
• Phonons in MoSe2/WSe2 van der Waals heterobilayer
• Exciton-activated effective phonon magnetic moment in monolayer MoS2
• Low-frequency Raman signature of Ag-intercalated few-layer MoS${}_2$
• Flat and tunable moire phonons in twisted transition-metal dichalcogenides
• Raman Forbidden Layer-Breathing Modes in Layered Semiconductor Materials Activated by Phonon and Optical Cavity Effects
• Chiral phonons in binary compounds $A$Bi ($A$ = K, Rb, Cs) with P2${}_1$/c structure
• Helicity resolved Raman spectroscopy of mono- and a few-layers thick PtSe${}_2$
• PARPHOM: PARallel PHOnon calculator for Moiré systems
• Two-Dimensional Transition Metal Dichalcogenides-Based Counter Electrodes for Dye-Sensitized Solar Cells
• Directing Monolayer Tungsten Disulfide Photoluminescence using a Bent Plasmonic Nanowire on a Mirror Cavity
• Phonon pseudoangular momentum in $\alpha$-MoO${}_3$
• Raman tensor for two-dimensional massive Dirac fermions
• Chiral phonon in the cubic system based on the Laves phase of $A$Bi${}_2$ ($A=$K, Rb, Cs)
• Divergent phonon angular momentum driven by temperature and strain
• Trapping the carrier in the spin-locked MoS2 atomic valley by absorption of chiral L-cysteine
• Plasmonic nanocavity-enabled universal detection of layer-breathing vibrations in two-dimensional materials
• Kolmogorov-Crespi Potential For Multilayer Transition Metal Dichalcogenides: Capturing Structural Transformations In Moiré Superlattices
• Mechanical Detuning of Exciton-Phonon Resonance in WS2
• Excitation energy dependence of Raman spectra of few-layer WS2
• Revealing the nanogeometry of WS2 nanoflowers by polarization-resolved Raman spectroscopy
• Quasi-bound layer-breathing phonons inside perfect dislocations of lattice-relaxed twisted bilayers