Experimental determination of Rashba and Dresselhaus parameters andg^*-factor anisotropy via Shubnikov-de Haas oscillations

Abstract

The spin splitting of conduction band electrons in inversion-asymmetric InGaAs/InP quantum wells (QWs) is studied by Shubnikov-de Haas measurements combining the analysis of beating patterns and coincidence measurements in doubly tilted magnetic fields. The method allows us to determine the absolute values of the Rashba and linear Dresselhaus spin-orbit interaction (SOI) coefficients, their relative sign and the full Landé g-tensor. This is achieved by analyzing the anisotropy of the beat node positions with respect to both polar and azimuthal angles between the magnetic field direction and the QW normal. We show that the SOI is dominated by a large Rashba coefficient together with a linear Dresselhaus coefficient that is 10% of the Rashba coefficient. Their relative sign is found to be positive. The g-tensor is found to have a marked out-of-plane anisotropy and a smaller but distinct inplane anisotropy due to SOI.

Mesoscopic g-factor renormalization for electrons in III-V interacting nanolayers

“…Experimentally, the g-factor renormalization in InGaAs nanolayers has been investigated by Kowalski et al [24] and, more recently, also by Herzog et al [8]. The large confinementinduced anisotropy of the g factor in InGaAs QWs was confirmed in both studies.…”

“…In this approximation, we neglect the much smaller off-diagonal elements, which include the in-plane anisotropy. We also neglect the bulk k-cubic Dresselhaus spin-orbit coupling contribution, which in these InGaAs QWs is much smaller than the Rashba one [8,42,43].…”

“…Due to the increasing interest in spintronics [6] and in new schemes for quantum computation, including the detection of Majorana fermions [7], much attention has been given lately to the renormalization of the electron g factor in semiconductor nanostructures [8][9][10][11][12][13][14][15][16][17][18]. The mesoscopic confining potential in semiconductor nanostructures further renormalizes the bulk effective g factor (already renormalized from the bare value 2) and introduces extra anisotropies, transforming scalar g factors into tensors.…”

“…After the work of many groups [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40], it is by now well established that the ground-state effective g factor for electrons confined in regular GaAs-like QWs (g QW ) varies with L w interpolating from the bulk barrier (AlGaAs) to the bulk well (GaAs) g factors, when L w goes from zero to a sufficiently large value; and that between these two bulk limits, g QW (L w ), depends on the magnetic-field orientation. The difference in the QW g factor between the magnetic-field orientations perpendicular and parallel to the interfaces gives the g-factor main anisotropy g QW (=g − g ⊥ ) which is the most direct and critical signature of the quantum confinement, and has been much investigated both theoretically [13,14,17,22,41] and experimentally [8,24,26,32,39]. QW structures made out of different compounds were investigated and it is known, for example, that except for very thin asymmetric wells [13], electrons in GaAs-like QWs have a positive anisotropy, i.e., g > g ⊥ , where g refers to an in-plane magnetic field configuration, while g ⊥ to a magnetic field along the growth direction (note, however, that the opposite definition of anisotropy is also used in the literature).…”

Magnetic stability for the Hartree-Fock ground state in two dimensional Rashba-Gauge electronic systems

“…Also,Ē x = eE x /αk 2 0 . With α = 4.62 × 10 −12 eV·m, which is typical for semiconducting InGaAs/InP asymmetric quantum wells, k −1 0 falls into the range of 44.63 nm with m ⋆ = 0.37m 0 and 76.38 nm for m ⋆ = 0.04m 0 in 2DEG In x Ga 1−x As [26,27]. For tunable Rashba energy on Bi x Pb 1−x /Ag (111) alloys, α reaches the value 3 × 10 −10 eV·m, with m ⋆ = 0.3m 0 and 1.2 < k −1 0 < 2.5 nm [28].…”