Microscopic Analysis of Lattice Distortion Effects in Rashba Systems

TL;DR

This paper theoretically investigates how dynamical lattice distortions influence Rashba spin-orbit coupling and induce various spin currents in a three-dimensional system with broken inversion symmetry.

Contribution

It introduces a model incorporating lattice distortions into Rashba systems, revealing modulation effects on spin currents and comparing different analytical approaches.

Findings

Lattice distortions modulate Rashba coupling terms.

Various spin currents are induced by lattice effects.

Comparison with local coordinate transformation methods.

Abstract

We theoretically study the effects of dynamical lattice distortion in a three-dimensional Rashba system based on a tight-binding model. Considering an $sp$-electron system on a tetragonal lattice with broken inversion symmetry, lattice distortions are incorporated through hopping-integral and crystal-axis modulations. The effective Hamiltonian for the $p_z$- or $s$-derived band is found to have Rashba modulation terms, which induce various types of spin currents, such as Rashba, quadrupolar, perpendicular, and helicity currents. The results are compared with those obtained by the method of local coordinate transformation.