Finely Controlled Approaches to Formation of Heusler-Alloy/Semiconductor Heterostructures for Spintronics

Abstract

We present recent progress of the low-temperature growth of Heusler-alloy/silicon(Si) or Heusler-alloy/germanium(Ge) heterostructures and of their applications for spintronics. First, a concept of the realization of the low-temperature heteroepitaxy for high-quality Heusler alloy/Si or Heusler alloy/Ge heterostructures is shown. Despite very low-growth temperatures, B2 or L2₁ ordered full-Heusler alloys are achieved. Next, by applying this concept to the growth of Ge on a Heusler alloy or a Heusler alloy on another Heusler alloy, we can also achieve unusual heterostructures for the possibility of novel spintronics applications. Finally, we demonstrate the pure spin current transport in Cu and Ge using these Heusler-alloy spin injectors and detectors. Our approaches will open new avenues for developing high-performance spintronic applications with Heusler alloys.