Influence of anisotropic magnetoresistance on nonlocal signals in Si-based multi-terminal devices with Fe electrodes

TL;DR

This study examines how anisotropic magnetoresistance affects nonlocal signals in silicon-based devices with ferromagnetic electrodes, highlighting structural influences on electric potential distribution crucial for spin transport analysis.

Contribution

It reveals the significant impact of AMR on nonlocal signals and discusses the challenges in achieving pure spin currents due to electric potential distribution in Si channels.

Findings

AMR significantly influences nonlocal signals in Si devices.

Pure spin current realization is hindered by electric potential distribution.

No clear spin-valve signals were observed.

Abstract

We have investigated the influence of anisotropic magnetoresistance (AMR) on nonlocal signals in Si-based multi-terminal devices with ferromagnetic Fe electrodes. The AMR of the Fe electrodes was found to have a significant influence on nonlocal signals when the in-plane device structure is not optimized. Moreover, realization of a pure spin current by spin diffusion was found to be virtually impossible because of the electric potential distribution in the depth direction in the Si channel. Although apparent signals indicating the spin-valve effect were not detected, we mainly present structural influence on the electric potential distribution which is indispensable for the analyses of spin-dependent transport.