Interface-based tuning of Rashba spin-orbit interaction in asymmetric oxide heterostructures with 3d electrons

Abstract

The Rashba effect plays important roles in emerging quantum materials physics and potential spintronic applications, entailing both the spin orbit interaction (SOI) and broken inversion symmetry. In this work, we devise asymmetric oxide heterostructures of LaAlO 3 //SrTiO 3 /LaAlO 3 (LAO//STO/LAO) to study the Rashba effect in STO with an initial centrosymmetric structure, and broken inversion symmetry is created by the inequivalent bottom and top interfaces due to their opposite polar discontinuities. Furthermore, we report the observation of a transition from the cubic Rashba effect to the coexistence of linear and cubic Rashba effects in the oxide heterostructures, which is controlled by the filling of Ti orbitals. Such asymmetric oxide heterostructures with initially centrosymmetric materials provide a general strategy for tuning the Rashba SOI in artificial quantum materials.

Evidence of weak antilocalization in quantum interference effects of (001) oriented La0.7Sr0.3MnO3–SrRuO3 superlattices

“…As the LSMO thickness increases, Δσ(H) of the [20 u:c: SRO/5 u:c: LSMO] Â15 superlattice shows a transition from WL to WAL with the increasing field. However, similar Δσ(H) has been observed in the SrIrO 3 grown on STO40 and LaAlO 3 //SrTiO 3 /LaAlO 3 heterostructure,41 which is explained by the modification of weak localization by spin-orbit coupling. The positive MR of the [20 u:c: SRO/3 u:c: LSMO] Â15 superlattice is attributed to spin-orbit coupling associated with magnetic anisotropy, i.e., spin and bond length fluctuation 42,43.…”

Organic-to-inorganic structural chirality transfer in a 2D hybrid perovskite and impact on Rashba-Dresselhaus spin-orbit coupling

“…So, the C 2 rotational axis for chiral NPB (corresponding to P2 1 space group) points along the Γ-Y path, thereby explaining the minimal spin-splitting along this direction. This configuration contrasts with conventional 2D Rashba systems such as inorganic quantum well (QW) heterostructures 32,47 or BiTeI 48 , which exhibit the C nV symmetry and where the C n (n = 2, 3) axis coincides with the stacking direction. Therefore, as suggested in earlier work on quasi-2D systems by Even and coworkers 32 , the situation in chiral NPB corresponds to a 1D problem with dominant SOC contributions only along the [100] crystallographic direction ( Fig.…”

Cubic Rashba Effect in the Surface Spin Structure of Rare-Earth Ternary Materials

“…Vivid examples are semiconductor quantum wells [7,8] and oxide surfaces and interfaces [9][10][11][12][13], which prominently feature the so-called cubic, R ð3Þ , Rashba effect responsible for the nonlinear (∝ jkj 3 ) dependence of the spin-orbit splitting of 2D heavy-hole states [14][15][16]. Remarkably, the EMF in the R ð3Þ model has a different symmetry from the R ð1Þ model, so that the in-plane pseudospin of the heavy hole rotates three times faster in moving around the Fermi contour and is no longer orthogonal to k everywhere [9,[17][18][19][20].…”