Variational analysis of the Rashba splitting in III–V semiconductor inversion layers

Abstract

A spin-dependent variational theory is used to analyze the Rashba spin-orbit splitting in two-dimensional electron gases formed in III-V semiconductor inversion layers. The spin split conduction subbands in CdTe/InSb, insulator/InAs, InP/InGaAs, InAlAs/InGaAs, and AlGaAs/GaAs heterojunctions are calculated. The theory, presented here in detail, is based on the 8 × 8 k · p Kane model and on the introduction of simple and convenient spin-dependent Fang-Howard trial functions, and leads to analytical expressions for the split subbands, as well as allows for a detailed knowledge of the Rashba spin-orbit coupling, including its explicit dependence on structure parameters and its decomposition into separate contributions. The Rashba coupling parameter and the population difference in the spin-split subbands, as experimentally determined from the beating pattern of the Shubnikov-de Haas (SdH) oscillations, are obtained as a function of the electron density (n s ). The separate contributions to the particularly large Rashba splitting in CdTe/InSb heterojunctions are also computed and discussed. It is shown, for example, that due to the spin-dependent boundary conditions, the direct Rashba spin-orbit coupling term in the effective Hamiltonian dominates the splitting only for n s > 10 10 cm −2 while it is the barrier penetration kinetic energy term that gives the largest contribution to the Rashba effect at lower densities.

Electrongfactor anisotropy in asymmetric III–V semiconductor quantum wells

“…QWs with different left and right barriers), focus on the small L limit where both the quantum and SIA effects are larger, and extend the above solution for * g L QW ( ) to the case of AQWs. Such low field perturbation solution has shown to be accurate in the  L 0 limit [6,[9][10][11], and reveal here an interesting g-factor anisotropy sign change in narrow AQWs that can be useful in different spintronic applications; a detailed derivation of the main results is provided.…”

“…g * is a fundamental parameter that determines the Zeeman splitting of the electronic states and depends on different quantum effects. For the most basic example, in GaAs/AlGaAs like quantum wells (QWs) the g factor is determined by the confined wave-function and by the mesoscopic (Rashba type) spin-orbit (SO) interaction at the interfaces [4][5][6][7]. Breaking of translation symmetry along the QW growth direction (zˆ) leads to an electron (leading-order) g-factor tensor in the following form: ( ) (i.e.…”

Effect of external electric field on the electronic properties of the AlAs/SiC van der Waals heterostructure

“…Considering the existence of vdW interaction between layers, the dispersion-corrected DFT method was adopted for correction as the PBE exchange–correlation function does not correctly describe weak interactions. 33 The energy cutoff value was set to 500 eV, and a Monkhorst–Pack k -mesh of 5 × 5 × 1 was selected in the Brillouin zone for structural optimization and energy calculations. The structures were optimized until the energy difference reached 1.0 × 10 −6 eV per atom with a force tolerance of 0.01 eV Å −1 , the maximum stress became 0.01 GPa, while the maximum displacement did not exceed 5.0 × 10 −4 Å.…”

“…In recent years, III–V semiconductor materials have received widespread attention due to their excellent optoelectronic properties. 24–33 Their characteristics, such as high carrier mobility and wide band gap, make them an emerging force in semiconductor materials. For example, GaN and AIN have been widely used in the field of optoelectronics.…”

Electron spin rotations induced by oscillating Rashba interaction in a quantum wire

“…The electric field E(r, t) = −∇ϕ (r, t) is calculated for the potential ϕ without inclusion of the conduction band offset at the wire/dielectric interface. 66 The wave vector 65 We assume that nanowire is grown along [111] crystallographic direction which allows us to neglect the Dresselhaus SOI. 65…”