Spin Injection Enhancement Through Schottky Barrier Superlattice Design

TL;DR

This paper proposes a novel superlattice design to enhance room-temperature spin injection efficiency from magnetic metals into InAs semiconductors by engineering Schottky barriers with high conductivity and spin lifetimes.

Contribution

It introduces a new InAs/AlSb superlattice structure that aligns conduction bands with metal Fermi levels to improve spin injection efficiency at room temperature.

Findings

Superlattice design achieves high conduction band alignment.

Enhanced spin lifetimes and conductivity in the superlattice.

Potential for high-efficiency spin injection from ferromagnetic metals.

Abstract

We predict it is possible to achieve high-efficiency room-temperature spin injection from a mag- netic metal into InAs-based semiconductors using an engineered Schottky barrier based on an InAs/AlSb superlattice. The Schottky barrier with most metals is negative for InAs and positive for AlSb. For such metals there exist InAs/AlSb superlattices with a conduction band edge perfectly aligned with the metal's Fermi energy. The initial AlSb layer can be grown to the thickness required to produce a desired interface resistance. We show that the conductivity and spin lifetimes of such superlattices are sufficiently high to permit efficient spin injection from ferromagnetic metals.