Strong evidence for d-electron spin transport at room temperature at a LaAlO3/SrTiO3 interface

TL;DR

This study demonstrates room-temperature spin transport in a d-electron 2DEG at LaAlO3/SrTiO3 interface with a relaxation length over 200 nm, challenging previous beliefs and opening new avenues in oxide-based spintronics.

Contribution

First experimental evidence of room-temperature spin transport in d-electron 2DEG at LaAlO3/SrTiO3 interface, revealing potential for oxide spintronics.

Findings

Spin relaxation length exceeds 200 nm at room temperature.

D-electron 2DEG can support long-range spin transport.

Counteracts previous assumptions about spin transport limitations in d-electron systems.

Abstract

A d-orbital electron has an anisotropic electron orbital and is a source of magnetism. The realization of a 2-dimensional electron gas (2DEG) embedded at a LaAlO3/SrTiO3 interface surprised researchers in materials and physical sciences because the 2DEG consists of 3d-electrons of Ti with extraordinarily large carrier mobility, even in the insulating oxide heterostructure. To date, a wide variety of physical phenomena, such as ferromagnetism and the quantum Hall effect, have been discovered in this 2DEG systems, demonstrating the ability of the d-electron 2DEG systems to provide a material platform for the study of interesting physics. However, because of both ferromagnetism and the Rashba field, long-range spin transport and the exploitation of spintronics functions have been believed difficult to implement in the d-electron 2DEG systems. Here, we report the experimental demonstration of room-temperature spin transport in the d-electron-based 2DEG at a LaAlO3/SrTiO3 interface, where the spin relaxation length is ca. exceeding 200 nm. Our finding, which counters the conventional understandings to d-electron 2DEGs, opens a new field of d-electron spintronics. Furthermore, this work highlights a novel spin function in the conductive oxide system.