Signatures of asymmetric and inelastic tunneling on the spin torque bias dependence

Abstract

The influence of structural asymmetries (barrier height and exchange splitting), as well as inelastic scattering (magnons and phonons) on the bias dependence of the spin transfer torque in a magnetic tunnel junction is studied theoretically using the free electron model. We show that they modify the "conventional" bias dependence of the spin transfer torque, together with the bias dependence of the conductance. In particular, both structural asymmetries and bulk (inelastic) scattering add {\em antisymmetric} terms to the perpendicular torque ($\propto V$ and $\propto j_e|V|$), while the interfacial inelastic scattering conserves the junction symmetry and only produces {\em symmetric} terms ($\propto |V{|}^n$, $n\in \mathbb{N}$). The analysis of spin torque and conductance measurements displays a signature revealing the origin (asymmetry or inelastic scattering) of the discrepancy.

References in corpus (6)

• Bias-driven large power microwave emission from MgO-based tunnel magnetoresistance devices
• Anomalous Bias Dependence of Spin Torque in Magnetic Tunnel Junctions
• Magnetoresistance and spin-transfer torque in magnetic tunnel junctions
• Ab initio studies of the spin-transfer torque in tunnel junctions
• Spin-transfer torque in magnetic tunnel junctions: Scattering theory
• Description of current-driven torques in magnetic tunnel junctions

Cited by in corpus (7)

• Time-resolved detection of spin-transfer-driven ferromagnetic resonance and spin torque measurement in magnetic tunnel junctions
• Signatures of electron-magnon interaction in charge and spin currents in magnetic tunnel junctions: A nonequilibrium many-body perturbation theory approach
• Analytical description of ballistic spin currents and torques in magnetic tunnel junctions
• First-principles quantum transport modeling of spin-transfer and spin-orbit torques in magnetic multilayers
• Robust spin transfer torque in antiferromagnetic tunnel junctions
• Spin Transfer Torque with Spin Diffusion in Magnetic Tunnel Junctions
• Twist in the bias-dependence of spin-torques in magnetic tunnel junctions