Spin splitting in 2D monochalcogenide semiconductors

Abstract

We report ab initio calculations of the spin splitting of the uppermost valence band (UVB) and the lowermost conduction band (LCB) in bulk and atomically thin GaS, GaSe, GaTe, and InSe. These layered monochalcogenides appear in four major polytypes depending on the stacking order, except for the monoclinic GaTe. Bulk and few-layer $\epsilon$- and $\gamma$-type, and odd-number $\beta$-type GaS, GaSe, and InSe crystals are noncentrosymmetric. The spin splittings of the UVB and the LCB near the $\Gamma$-point in the Brillouin zone are finite, but still smaller than those in a zinc-blende semiconductor such as GaAs. On the other hand, the spin splitting is zero in centrosymmetric bulk and even-number few-layer $\beta$-type GaS, GaSe, and InSe, owing to the constraint of spatial inversion symmetry. By contrast, GaTe exhibits zero spin splitting because it is centrosymmetric down to a single layer. In these monochalcogenide semiconductors, the separation of the non-degenerate conduction and valence bands from adjacent bands results in the suppression of Elliot-Yafet spin relaxation mechanism. Therefore, the electron- and hole-spin relaxation times in these systems with zero or minimal spin splittings are expected to exceed those in GaAs when the D'yakonov-Perel' spin relaxation mechanism is also suppressed.

7 pages, 5 figures

References in corpus (14)

• Spintronics: Fundamentals and applications
• 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
• Rashba spin splitting in two-dimensional electron and hole systems
• Band Structure and Optical Transitions in Atomic Layers of Hexagonal Gallium Chalcogenides
• Ab-initio Prediction of Conduction Band Spin Splitting in Zincblende Semiconductors
• A unified theory of spin-relaxation due to spin-orbit coupling in metals and semiconductors
• Prediction of large linear-in-k spin splitting for holes in the 2D GaAs/AlAs system
• Angle-resolved photoemission study and first principles calculation of the electronic structure of GaTe
• Optical Spin Polarization Dynamics in GaSe Nanoslabs
• Near Unity Optical Spin Polarization in GaSe Nanoslabs
• Hole spin relaxation in intrinsic and $p$-type bulk GaAs

Cited by in corpus (15)

• Tuning Rashba Spin-Orbit Coupling in Gated Multilayer InSe
• Symmetry, distorted bandstructure, and spin-orbit coupling of (group-III) metal-monochalcogenide monolayers
• Layer- and Frequency-Dependent Second Harmonic Generation in Reflection from GaSe Atomic Crystals
• Spin-orbit coupling, optical transitions, and spin pumping in mono- and few-layer InSe
• High-performance two-dimensional p-type transistors based on GaSe layers: an ab-initio study
• Strong Modulation of Optical Properties in Rippled 2D GaSe via Strain Engineering
• Evidence of Direct Electronic Band Gap in two-dimensional van der Waals Indium Selenide crystals
• Resonance and antiresonance in Raman scattering in GaSe and InSe crystals
• Exciton spin dynamics in GaSe
• Electron-Electron Interactions in 2D Semiconductor InSe
• Layer-dependent optically-induced spin polarization in InSe
• Characteristics of Interlayer Tunneling Field Effect Transistors Computed by a "DFT-Bardeen" Method
• Layer- and Gate-tunable Spin-Orbit Coupling in a High Mobility Few-Layer Semiconductor
• Flavor Quantum Dots and Artificial Quark Model in Transition Metal Dichalcogenides
• Enhanced Light Emission from the Ridge of Two-dimensional InSe Flakes