Gate Tunable In- and Out-Of-Plane Spin-Orbit Coupling and Spin Splitting Anisotropy at LaAlO3/SrTiO3 (110) Interface

Abstract

Manipulating spin-orbit coupling (SOC) is important for devices such as spin-orbit torque based memory and its understanding is neccessary to answer several fundamental open questions in triplet state superconductivity, topological insulators and Majorana fermions. Here we report spin splitting of 25 meV at the LaAlO3/SrTiO3 (110) interface for in-plane spins at a current density of 1.4x104 A/cm2, which is large compared to that found in semiconductor heterostructures or the LaAlO3/SrTiO3 (100) interface, and in addition it is anisotropic. The anisotropy arises from the difference in electron effective mass along the [001] and [1-10] directions. Our study predicts a spin splitting energy > 1000 meV at a current density of 107 A/cm2, which is enormous compared to metallic systems and will be an ideal spin polarized source. In addition to the in-plane effect, there is an unexpected gate-tunable out-of-plane SOC at the LaAlO3/SrTiO3 (110) interface when the spins lie out-of-plane due to broken symmetry in the plane of the interface. We demonstrate that this can be manipulated by varying the LaAlO3 thickness showing that this interface can be engineered for spin-orbit torque devices.

17 pages, 5 figures in Advanced Electronic Materials (Wiley) Vol. 1, Issue 8, 2015

References in corpus (7)

• Magnetic effects at the interface between nonmagnetic oxides
• Spin Transfer Torque Generated by the Topological Insulator Bi_2Se_3
• A spin triplet supercurrent through the half-metallic ferromagnet CrO2
• Theory of spin-orbit coupling at LaAlO3/SrTiO3 interfaces and SrTiO3 surfaces
• Avoiding the polarization catastrophe in LaAlO3 overlayers on SrTiO3(001) through a polar distortion
• High mobility conduction at (110) and (111) LaAlO3/SrTiO3 interfaces
• Current-driven spin orbit field in LaAlO3/SrTiO3 heterostructures

Cited by in corpus (13)

• Planar Hall Effect and Anisotropic Magnetoresistance in a polar-polar interface of LaVO${}_3$-KTaO${}_3$ with strong spin-orbit coupling
• Band Structure and Spin-Orbital Texture of the (111)-KTaO3 Two-Dimensional Electron Gas
• Atomically precise lateral modulation of a two-dimensional electron liquid in anatase TiO2 thin films
• Mechanism, time-reversal symmetry and topology of superconductivity in noncentrosymmetric systems
• Anisotropic, multi-carrier transport at the (111) LaAlO${}_3$/SrTiO${}_3$ interface
• Magnetoresistance in the superconducting state at the (111) LaAlO${}_3$/SrTiO${}_3$ interface
• Anisotropic electronic transport of the two-dimensional electron system in Al2O3/SrTiO3 heterostructures
• Experimental Evidence of t2g Electron-Gas Rashba Interaction Induced by Asymmetric Orbital Hybridization
• Signatures of Electronic Nematicity in (111) LaAlO${}_3$/SrTiO${}_3$ Interfaces
• La interstitial defect-induced insulator-metal transition in oxide heterostructures LaAlO3/SrTiO3
• Electrostatic tuning of magnetism at the conducting (111) (La${}_{0.3}$Sr${}_{0.7}$)(Al${}_{0.65}$Ta${}_{0.35}$)/SrTiO${}_3$ interface
• Anisotropic electronic transport and Rashba effect of the two-dimensional electron system in (110) SrTiO${}_3$-based heterostructures
• High-quality Nano-patterning of Oxide Interfaces Using Transferred Gold Mask