Topologically protected spin diffusion and spin generator using chalcogenide superlattices

Junji Tominaga,Shuichi Murakami,Satoshi Sumi,Hiroyuki Awano,Noriyuki Miyata

doi:10.1038/s41699-020-0157-8

Abstract

Spintronics is expected to be the basis for future ultra-low-energy nanoelectronic devices. To operate such devices at room temperature, amplifiers, batteries, capacitors, as well as spin current sources are required. Here we report a chalcogenide superlattice composed of GeTe and Sb2Te3 layers that have a topologically protected spin diffusion length exceeding 100 μm at room temperature. A spin generator is demonstrated by combining magnetic injectors (TbFeCo) with this superlattice. The spin current was found to increase exponentially with the number of superlattice periods. We used this effect to demonstrate a 15-fold increase in the spin current. In addition, spin rectification is possible by growing the superlattice layers with atomic-level thickness accuracy. The reported chalcogenide superlattice spin generators and rectifiers open new opportunities to design low-energy spintronic integrated circuits and quantum computers.

Highlights

Spintronics is key to realizing ultra-low power electronics[1,2,3,4,5,6,7,8,9]
We show that the spin diffusion length of the Ge2Te2-Sb2Te3 SLs is over 100 μm at room temperature
The Sb2Te3 layer is covalently bonded with a Te-Sb-Te-Sb-Te atomic stacking sequence, whereas the units are weakly held together by the van der Waals force

Summary

Introduction

Spintronics is key to realizing ultra-low power electronics[1,2,3,4,5,6,7,8,9]. An example of spintronic device is a magnetoresistive nonvolatile memory. We show that the spin diffusion length of the Ge2Te2-Sb2Te3 SLs is over 100 μm at room temperature. In the vicinity of the magnetic domain transition in the spin injector (TbFeCo), VISH signals are clearly changed (Fig. 1c) and reversed in the opposite magnetic field sweeping.

Results

Conclusion