Bias dependent features in spin transport as a probe of the conduction band minima in Si

TL;DR

This paper investigates how bias-dependent features in spin transport through a Si-based spin valve reveal information about conduction band minima, utilizing BEMM to probe local interface effects and spin flip scattering.

Contribution

It demonstrates the use of BEMM to explore local spin transport variations at a textured Si interface, revealing bias-dependent features linked to conduction band minima.

Findings

Bias dependence of spin transport reveals conduction band minima in Si.

Local interface strain and dislocations influence spin flip scattering.

BEMM effectively probes local spin transport differences.

Abstract

Unusual features in the bias dependence of spin transport are observed in a Co/Au/NiFe spin valve fabricated on a highly textured Cu(100)/Si(100) Schottky interface, exploiting the local probing capabilities of a Ballistic electron magnetic microscope (BEMM). This arises due to local differences in the strain and the presence of misfit dislocations at the Schottky interface that enhances spin flip scattering and broadens the energy and angular distribution of the transmitted electrons. Cumulatively, these enable the transmitted hot electrons to probe the different conduction band minima in Si, giving rise to such bias dependent features in the magnetocurrent. This study reveals new insights into the spin dependence of transmission in an indirect band gap semiconductor as Si and highlights the unique capabilities of BEMM in probing local differences in spin transport across such textured interfaces.