Origin of inverse Rashba-Edelstein effect at Cu/Bi interface using lateral spin valves

TL;DR

This paper investigates the spin transport and spin-to-charge conversion at the Cu/Bi interface, revealing the inverse Rashba-Edelstein effect and its temperature-dependent behavior, with implications for spintronics in 2D systems.

Contribution

It demonstrates the occurrence of the inverse Rashba-Edelstein effect at the Cu/Bi interface and analyzes its temperature-dependent sign change, advancing understanding of spin-orbit phenomena.

Findings

Strong spin absorption at Bi surface causes ultra-short spin diffusion lengths.

Spin-to-charge conversion is observed and linked to the inverse Rashba-Edelstein effect.

Temperature influences the direction of the induced charge current.

Abstract

The spin transport and spin-to-charge current conversion properties of bismuth are investigated using permalloy/copper/bismuth (Py/Cu/Bi)lateral spin valve structures. The spin current is strongly absorbed at the surface of Bi, leading to ultra-short spin diffusion lengths. A spin-to-charge current conversion is measured, which is attributed to the inverse Rashba-Edelstein effect at the Cu/Bi interface. The spin-current-induced charge current is found to change direction with increasing temperature. A theoretical analysis relates this behavior to the complex spin structure and dispersion of the surface states at the Fermi energy. The understanding of this phenomenon opens novel possibilities to exploit spin-orbit coupling to create, manipulate, and detect spin currents in 2D systems.