Effects of electron correlation on resonant Edelstein and inverse-Edelstein effects

TL;DR

This paper investigates how electron-electron interactions influence the resonant Edelstein and inverse Edelstein effects, revealing the role of chiral-spin modes and their splitting in multi-valley systems.

Contribution

It provides a detailed analysis of electron correlation effects on spin-orbit induced phenomena in 2D electron systems, highlighting the role of chiral-spin modes and valley interactions.

Findings

Resonances occur at frequencies of spin-chiral collective modes.

Electron correlation splits in-plane spin modes into two in multi-valley systems.

Spectral weight distribution varies with intra- and inter-valley interactions.

Abstract

Spin-orbit coupling in systems with broken inversion symmetry gives rise to the Edelstein effect, which is the induced spin polarization in response to an applied electric field or current, and the inverse Edelstein effect, which is the induced electric current in response to an oscillatory magnetic field or spin polarization. At the same time, an interplay between spin-orbit coupling and electron-electron interaction leads to a special type of collective excitations -- chiral-spin modes -- which are oscillations of spin polarization in the absence of a magnetic field. As a result, both Edelstein and inverse Edelstein effects exhibit resonances at the frequencies of spin-chiral collective modes. Here, we present a detailed study of the effect of electron correlation on the Edelstein and inverse Edelstein effects in a single-valley two-dimensional electron gas and a multi-valley Dirac system with proximity-induced spin-orbit coupling. While the chiral-spin modes involve both in-plane and out-of-plane oscillations of spins, we show that only the in-plane modes are responsible for the above resonances. In the multi-valley system, electron correlation splits the in-plane modes into two. We also study the spectral weight distribution between the two resonances over a large parameter space of intra- and inter-valley interactions.