Electrical injection and detection of spin-polarized electrons in silicon through an Fe_3Si/Si Schottky tunnel barrier

TL;DR

This paper reports the successful electrical injection and detection of spin-polarized electrons in silicon using Fe_3Si/Si Schottky tunnel barriers, with enhanced conductance and measurable spin signals at low temperatures.

Contribution

It introduces a novel Fe_3Si/Si Schottky-tunnel-barrier contact with delta-doping to improve spin injection efficiency in silicon.

Findings

Enhanced tunnel conductance in Fe_3Si/Si Schottky diodes.

Detection of nonlocal spin signals in silicon at low temperatures.

Effective spin injection demonstrated through four-probe measurements.

Abstract

We demonstrate electrical injection and detection of spin-polarized electrons in silicon (Si) using epitaxially grown Fe_3Si/Si Schottky-tunnel-barrier contacts. By an insertion of a delta-doped n^+-Si layer (~ 10^19 cm^-3) near the interface between a ferromagnetic Fe_3Si/Si contact and a Si channel (~ 10^15 cm^-3), we achieve a marked enhancement in the tunnel conductance for reverse-bias characteristics of the Fe_3Si/Si Schottky diodes. Using laterally fabricated four-probe geometries with the modified Fe_3Si/Si contacts, we detect nonlocal output signals which originate from the spin accumulation in a Si channel at low temperatures.