Electrical spin injection and accumulation in CoFe/MgO/Ge contacts at room temperature

TL;DR

This paper demonstrates room-temperature electrical spin injection and detection in CoFe/MgO/n-Ge contacts, revealing significant spin signals and analyzing their bias and temperature dependencies to understand spin transport properties.

Contribution

It reports the first all-electrical spin injection and detection in CoFe/MgO/n-Ge contacts at room temperature with detailed analysis of spin lifetime and diffusion length.

Findings

Spin signal of ~170 kΩ μm^2 observed at RT

Spin lifetime of ~120 ps in Ge

Spin diffusion length of ~683 nm in Ge

Abstract

We first report the all-electrical spin injection and detection in CoFe/MgO/moderately doped n-Ge contact at room temperature (RT), employing threeterminal Hanle measurements. A sizable spin signal of ~170 k{\Omega} {\mu}m^2 has been observed at RT, and the analysis using a single-step tunneling model gives a spin lifetime of ~120 ps and a spin diffusion length of ~683 nm in Ge. The observed spin signal shows asymmetric bias and temperature dependences which are strongly related to the asymmetry of the tunneling process.