Effect of vertex corrections on the enhancement of Gilbert damping in spin pumping into a two-dimensional electron gas

TL;DR

This paper investigates how vertex corrections influence the enhancement of Gilbert damping in spin pumping into a 2DEG with combined Rashba and Dresselhaus spin-orbit interactions, revealing significant effects near specific interaction ratios.

Contribution

It demonstrates that vertex corrections significantly amplify Gilbert damping due to elastic spin-flipping when the spin-orbit interaction ratio approaches a critical value.

Findings

Vertex correction strongly enhances Gilbert damping near a specific spin-orbit ratio.

Damping due to magnon absorption shows minimal change with vertex correction.

Resonant frequency shift is also significantly affected by vertex correction.

Abstract

We theoretically consider the effect of vertex correction on spin pumping from a ferromagnetic insulator (FI) into a two-dimensional electron gas (2DEG) in which the Rashba and Dresselhaus spin-orbit interactions coexist. The Gilbert damping in the FI is enhanced by elastic spin-flipping or magnon absorption. We show that the Gilbert damping due to elastic spin-flipping is strongly enhanced by the vertex correction when the ratio of the two spin-orbit interactions is near a special value at which the spin relaxation time diverges while that due to magnon absorption shows only small modification. We also show that the shift in the resonant frequency due to elastic spin-flipping is strongly enhanced in a similar way as the Gilbert damping.