The effect of spin drift on spin accumulation voltages in highly-doped Si

TL;DR

This study examines how spin drift influences spin accumulation voltages in highly-doped silicon, revealing different effects in non-local 4-terminal and 3-terminal measurement schemes, with the latter showing significant bias electric field dependence.

Contribution

It provides a quantitative analysis of spin drift effects on spin signals in highly-doped Si using spin drift-diffusion equations, clarifying the bias dependence in 3-terminal measurements.

Findings

NL-4T spin signals unaffected by spin drift

NL-3T spin signals strongly modulated by bias electric field

Quantitative explanation using spin drift-diffusion model

Abstract

An investigation was carried out into the effect of spin drift on spin accumulation signals in highly-doped Si using non-local 4-terminal (NL-4T) and 3-terminal (NL-3T) methods. The spin signals in the NL-4T scheme were not affected by spin drift, and the bias dependence was governed by whether spins were injected into or extracted from the Si channel. In contrast, the spin signal was strongly modulated by the bias electric field in the NL-3T scheme. The bias electric field dependence of the spin signals in the NL-3T method was quantitatively clarified using the spin drift-diffusion equation, and the results can be reasonably explained.