Detection of spin-orbit coupling of surface electron layer via reciprocal spin Hall effect in InN films

Abstract

Swirly photocurrent in InN films arising from reciprocal spin Hall effect (RSHE) is observed under normal incidence of circularly polarized light at room temperature. It is found that the swirly current is a superposition of the RSHE currents from the surface and bulk layer of InN. The effective spin-orbit coupling coefficient (SOC) in the surface electron layer is suggested to be of opposite sign to that in the bulk. The results constitute a comprehensive understanding of the role of surface electron layer in spin transport in InN. This work reveals an approach to explore spin-orbit coupling in systems like InN.

Photoinduced Inverse Spin Hall Effect of Surface States in the Topological Insulator Bi2Se3

“…However, there is often a 2DEG existing at the surface of a 3D TI that can contribute to the electric transport or optical response, , and there are very few methods that can clearly distinguish its contributions from that of SSs . The photoinduced inverse spin Hall effect (PISHE) is an attractive technique as it is sensitive to surface states and has been used to study the surface electron accumulation layer in InN films . It offers a method for detecting the inverse spin Hall effect (ISHE) or the inverse Rashba–Edelstein effect at room temperature. , Furthermore, it is also a powerful tool to manipulate electron spins in nonmagnetic semiconductors without applying of magnetic field or introducing ferromagnetic elements …”

“…The circularly polarized light spot induces spin polarized carriers with Gaussian distribution in space in the unsaturated absorption area. A diffuse spin current is generated flowing along the radial direction due to the gradient of the photogenerated spin polarized carrier densities, and then owing to the spin-momentum locking effect or to the ISHE effect, the spin polarized carriers show a transverse displacement in the axial direction, which can be described by a spin transverse force, leading to a swirly current (named as PISHE current) around the light spot. , The spin transverse force was first proposed by Shen and then was applied to explain the experiments in refs and . The optically injected spin current in 2DEG was first reported by Cui et al The PISHE current can be extracted by fitting the experimental data of light polarization dependence of photocurrent J to the following equation: Here, J PISHE is a helicity-dependent photocurrent, and L 1 and L 2 are helicity-independent photocurrents, named as anomalous linear photogalvanic effect (ALPGE), which is related to the linearly polarized light and can be attributed to the optical momentum alignment effect. , J 0 is the background photocurrent that is helicity-independent and originates from the photovoltaic effect, the thermoelectric effect, or the Dember effect .…”

The Luttinger-Kohn theory for multiband Hamiltonians: A revision of ellipticity requirements

“…The conduction band error err CB = 8.352 meV signifies that the correct dispersion of CB can be recovered almost perfectly by selecting the appropriate |B|. These stated differences between the obtained dispersion and the one for original parameter sets are caused by the non-zero spin-splitting of the CB states for B = 0, which is also witnessed experimentally 64,65 . To illustrate the effects of spin-splitting and visualize the behaviour of adjustment error, we provide in FIG.…”

Quantum transport and spin properties of the carriers in Ⅲ-nitride heterostructures

“…Ganichev 第一次将 CPGE 运用于研究半导体结构中的能带自旋分裂以 及自旋轨道耦合效应. 随后的研究还提出了自旋光 电流效应(Spin Galvanic Effect, SGE) [45] , 反常圆偏振 光电流效应(Anomalous CPGE, ACPGE) [46][47][48] , 以及 光致反常霍尔效应(Anomalous Hall Effect, AHE) [49] .…”