Spin-orbit coupling, optical transitions, and spin pumping in mono- and few-layer InSe

Abstract

We show that spin-orbit coupling (SOC) in InSe enables the optical transition across the principal band gap to couple with in-plane polarized light. This transition, enabled by $p_{x,y}\leftrightarrow p_z$ hybridization due to intra-atomic SOC in both In and Se, can be viewed as a transition between two dominantly $s$- and $p_z$-orbital based bands, accompanied by an electron spin-flip. Having parametrized $\mathbf{k}\cdot \mathbf{p}$ theory using first principles density functional theory we estimate the absorption for ${\sigma }^{\pm }$ circularly polarized photons in the monolayer as $\sim 1.5\%$, which saturates to $\sim 0.3\%$ in thicker films ($3-5$ layers). Circularly polarized light can be used to selectively excite electrons into spin-polarized states in the conduction band, which permits optical pumping of the spin polarization of In nuclei through the hyperfine interaction.

arXiv commentTo appear in Phys. Rev. B

References in corpus (22)

• Atomically thin MoS2: A new direct-gap semiconductor
• Optical Generation of Excitonic Valley Coherence in Monolayer WSe2
• High Electron Mobility, Quantum Hall Effect and Anomalous Optical Response in Atomically Thin InSe
• Strong light-matter coupling in two-dimensional atomic crystals
• Low-temperature photocarrier dynamics in monolayer MoS2
• Non-linear Optical Spectroscopy of Excited Exciton States for Efficient Valley Coherence Generation in WSe2 Monolayers
• Valley-selective optical Stark effect in monolayer WS2
• Tunable Magnetism and Half-Metallicity in Hole-doped Monolayer GaSe
• Electrons and phonons in single layers of hexagonal indium chalcogenides from ab initio calculations
• Fast multicolor photodetectors based on graphene-contacted p-GaSe/n-InSe van der Waals heterostructures
• Controlling the Spontaneous Emission Rate of Monolayer MoS${}_2$ in a Photonic Crystal Nanocavity
• Band Structure and Optical Transitions in Atomic Layers of Hexagonal Gallium Chalcogenides
• Mexican Hat and Rashba Bands in Few-Layer van der Waals Materials
• Two-dimensional InSe as a potential thermoelectric material
• Control of Two-Dimensional Excitonic Light Emission via Photonic Crystal
• Tunable Quasiparticle Band Gap in Few Layer GaSe/graphene Van der Waals Heterostructures
• Electronic and optical properties of two-dimensional InSe from a DFT-parameterized tight-binding model
• Charge Transfer and Functionalization of Monolayer InSe by Physisorption of Small Molecules for Gas Sensing
• Bistability of the Nuclear Polarisation created through optical pumping in InGaAs Quantum Dots
• Spin splitting in 2D monochalcogenide semiconductors
• Symmetry, distorted bandstructure, and spin-orbit coupling of (group-III) metal-monochalcogenide monolayers
• Defects and oxidation resilience in $InSe$

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• Indirect to direct gap crossover in two-dimensional InSe revealed by ARPES
• Experimental identification of critical condition for drastically enhancing thermoelectric power factor of two-dimensional layered materials
• Infrared-to-violet tunable optical activity in atomic films of GaSe, InSe, and their heterostructures
• The optical properties of few-layer InSe
• Hybrid $\mathbf{k}\cdot \mathbf{p}$-tight-binding model for intersubband optics in atomically thin InSe films
• Tunable spin-orbit coupling in two-dimensional InSe
• Layer-dependent optically-induced spin polarization in InSe
• Coulomb drag in metal monochalcogenides double-layer structures with Mexican-hat band dispersions