Origin of the Magnetoresistance in Oxide Tunnel Junctions Determined through Electric Polarization Control of the Interface

Hisashi Inoue; Adrian G Swartz; Nicholas J Harmon; Takashi Tachikawa; Yasuyuki Hikita; Michael E Flatté; Harold Y Hwang

doi:10.1103/PhysRevX.5.041023

Back

Origin of the Magnetoresistance in Oxide Tunnel Junctions Determined through Electric Polarization Control of the Interface

Journal article

Open access

Peer reviewed

Origin of the Magnetoresistance in Oxide Tunnel Junctions Determined through Electric Polarization Control of the Interface

Hisashi Inoue, Adrian G Swartz, Nicholas J Harmon, Takashi Tachikawa, Yasuyuki Hikita, Michael E Flatté and Harold Y Hwang

Physical review. X, Vol.5(4), p.041023

11/2015

DOI: 10.1103/PhysRevX.5.041023

Files and links (1)

url

https://doi.org/10.1103/PhysRevX.5.041023View

Published (Version of record) Open Access

Abstract

The observed magnetoresistance (MR) in three-terminal (3T) ferromagnet-nonmagnet (FM-NM) tunnel junctions has historically been assigned to ensemble dephasing (Hanle effect) of a spin accumulation, thus offering a powerful approach for characterizing the spin lifetime of candidate materials for spintronics applications. However, due to crucial discrepancies of the extracted spin parameters with known materials properties, this interpretation has come under intense scrutiny. By employing epitaxial artificial dipoles as the tunnel barrier in oxide heterostructures, the band alignments between the FM and NM channels can be controllably engineered, providing an experimental platform for testing the predictions of the various spin accumulation models. Using this approach, we have been able to definitively rule out spin accumulation as the origin of the 3T MR. Instead, we assign the origin of the magnetoresistance to spin-dependent hopping through defect states in the barrier, a fundamental phenomenon seen across diverse systems. A theoretical framework is developed that can account for the signal amplitude, linewidth, and anisotropy.

Details

Title: Subtitle: Origin of the Magnetoresistance in Oxide Tunnel Junctions Determined through Electric Polarization Control of the Interface
Creators: Hisashi Inoue - Geballe Laboratory for Advanced Materials
Adrian G Swartz - Geballe Laboratory for Advanced Materials
Nicholas J Harmon - University of Iowa
Takashi Tachikawa - The University of Tokyo
Yasuyuki Hikita - SLAC National Accelerator Laboratory
Michael E Flatté - University of Iowa
Harold Y Hwang - SLAC National Accelerator Laboratory
Resource Type: Journal article
Publication Details: Physical review. X, Vol.5(4), p.041023
DOI: 10.1103/PhysRevX.5.041023
ISSN: 2160-3308
eISSN: 2160-3308
Grant note: DOI: 10.13039/100000015, name: U.S. Department of Energy, award: DE-AC02-76SF00515; DOI: 10.13039/100007245, name: Microelectronics Advanced Research Corporation; DOI: 10.13039/100000185, name: Defense Advanced Research Projects Agency; name: C-SPIN
Language: English
Date published: 11/2015
Academic Unit: Electrical and Computer Engineering; Physics and Astronomy
Record Identifier: 9984199949002771

Metrics

60 Record Views

40 Times Cited - Web of Science