Gate-tunable Rashba spin-orbit coupling and spin polarization at diluted oxide interfaces

Yulin Gan, Yu Zhang, Dennis Valbjørn Christensen, Nini Pryds, Yunzhong Chen*

*Corresponding author for this work

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Abstract

A diluted oxide interface of LaAl1−xMnxO/SrTiO3 (LAMO/STO) provides a new way of tuning the ground states of the interface between the two band insulators of LAO and STO from metallic/superconducting to highly insulating. Increasing the Mn doping level (x) leads to a delicate control of the carrier density as well as a raise in the electron mobility and spin polarization. Herein, we demonstrate a tunable Rashba spin-orbit coupling (SOC) and spin polarization of LAMO/STO (0.2≤x≤0.3) by applying a back gate. The presence of SOC causes splitting of the energy band into two branches by a spin splitting energy. The maximum spin splitting energy depends on the Mn doping and decreases with the increasing Mn content and then vanishes at x=0.3. The carrier density dependence of the spin splitting energy for different compositions shows a dome-shaped behavior with a maximum at different normalized carrier densities. These findings have not yet been observed in LAO/STO interfaces. A fully back-gate-tunable spin-polarized two-dimensional electron liquid is observed at the interface with x=0.3 where only dxy orbits are populated (5.3×1012cm−2≤ns≤1.0×1013cm−2). The present results shed light on unexplored territory in SOC at STO-based oxide heterostructures and make LAMO/STO an intriguing platform for spin-related phenomena in 3d electron systems.
Original languageEnglish
Article number125134
JournalPhysical Review B (Condensed Matter and Materials Physics)
Volume100
Issue number12
Number of pages8
ISSN1098-0121
DOIs
Publication statusPublished - 2019

Cite this

@article{072f778cbfd14d858e7b128c373b5789,
title = "Gate-tunable Rashba spin-orbit coupling and spin polarization at diluted oxide interfaces",
abstract = "A diluted oxide interface of LaAl1−xMnxO/SrTiO3 (LAMO/STO) provides a new way of tuning the ground states of the interface between the two band insulators of LAO and STO from metallic/superconducting to highly insulating. Increasing the Mn doping level (x) leads to a delicate control of the carrier density as well as a raise in the electron mobility and spin polarization. Herein, we demonstrate a tunable Rashba spin-orbit coupling (SOC) and spin polarization of LAMO/STO (0.2≤x≤0.3) by applying a back gate. The presence of SOC causes splitting of the energy band into two branches by a spin splitting energy. The maximum spin splitting energy depends on the Mn doping and decreases with the increasing Mn content and then vanishes at x=0.3. The carrier density dependence of the spin splitting energy for different compositions shows a dome-shaped behavior with a maximum at different normalized carrier densities. These findings have not yet been observed in LAO/STO interfaces. A fully back-gate-tunable spin-polarized two-dimensional electron liquid is observed at the interface with x=0.3 where only dxy orbits are populated (5.3×1012cm−2≤ns≤1.0×1013cm−2). The present results shed light on unexplored territory in SOC at STO-based oxide heterostructures and make LAMO/STO an intriguing platform for spin-related phenomena in 3d electron systems.",
author = "Yulin Gan and Yu Zhang and Christensen, {Dennis Valbj{\o}rn} and Nini Pryds and Yunzhong Chen",
year = "2019",
doi = "10.1103/PhysRevB.100.125134",
language = "English",
volume = "100",
journal = "Physical Review B (Condensed Matter and Materials Physics)",
issn = "1098-0121",
publisher = "American Physical Society",
number = "12",

}

TY - JOUR

T1 - Gate-tunable Rashba spin-orbit coupling and spin polarization at diluted oxide interfaces

AU - Gan, Yulin

AU - Zhang, Yu

AU - Christensen, Dennis Valbjørn

AU - Pryds, Nini

AU - Chen, Yunzhong

PY - 2019

Y1 - 2019

N2 - A diluted oxide interface of LaAl1−xMnxO/SrTiO3 (LAMO/STO) provides a new way of tuning the ground states of the interface between the two band insulators of LAO and STO from metallic/superconducting to highly insulating. Increasing the Mn doping level (x) leads to a delicate control of the carrier density as well as a raise in the electron mobility and spin polarization. Herein, we demonstrate a tunable Rashba spin-orbit coupling (SOC) and spin polarization of LAMO/STO (0.2≤x≤0.3) by applying a back gate. The presence of SOC causes splitting of the energy band into two branches by a spin splitting energy. The maximum spin splitting energy depends on the Mn doping and decreases with the increasing Mn content and then vanishes at x=0.3. The carrier density dependence of the spin splitting energy for different compositions shows a dome-shaped behavior with a maximum at different normalized carrier densities. These findings have not yet been observed in LAO/STO interfaces. A fully back-gate-tunable spin-polarized two-dimensional electron liquid is observed at the interface with x=0.3 where only dxy orbits are populated (5.3×1012cm−2≤ns≤1.0×1013cm−2). The present results shed light on unexplored territory in SOC at STO-based oxide heterostructures and make LAMO/STO an intriguing platform for spin-related phenomena in 3d electron systems.

AB - A diluted oxide interface of LaAl1−xMnxO/SrTiO3 (LAMO/STO) provides a new way of tuning the ground states of the interface between the two band insulators of LAO and STO from metallic/superconducting to highly insulating. Increasing the Mn doping level (x) leads to a delicate control of the carrier density as well as a raise in the electron mobility and spin polarization. Herein, we demonstrate a tunable Rashba spin-orbit coupling (SOC) and spin polarization of LAMO/STO (0.2≤x≤0.3) by applying a back gate. The presence of SOC causes splitting of the energy band into two branches by a spin splitting energy. The maximum spin splitting energy depends on the Mn doping and decreases with the increasing Mn content and then vanishes at x=0.3. The carrier density dependence of the spin splitting energy for different compositions shows a dome-shaped behavior with a maximum at different normalized carrier densities. These findings have not yet been observed in LAO/STO interfaces. A fully back-gate-tunable spin-polarized two-dimensional electron liquid is observed at the interface with x=0.3 where only dxy orbits are populated (5.3×1012cm−2≤ns≤1.0×1013cm−2). The present results shed light on unexplored territory in SOC at STO-based oxide heterostructures and make LAMO/STO an intriguing platform for spin-related phenomena in 3d electron systems.

U2 - 10.1103/PhysRevB.100.125134

DO - 10.1103/PhysRevB.100.125134

M3 - Journal article

VL - 100

JO - Physical Review B (Condensed Matter and Materials Physics)

JF - Physical Review B (Condensed Matter and Materials Physics)

SN - 1098-0121

IS - 12

M1 - 125134

ER -