In situ investigation of conducting interface formation in LaAlO3/SrTiO3 heterostructure

Hyang Keun Yoo; Luca Moreschini; Aaron Bostwick; Andrew L. Walter; Tae Won Noh; Eli Rotenberg; Young Jun Chang

doi:10.1016/j.cap.2021.04.027

In situ investigation of conducting interface formation in LaAlO₃/SrTiO₃ heterostructure

Hyang Keun Yoo, Luca Moreschini, Aaron Bostwick, Andrew L. Walter, Tae Won Noh, Eli Rotenberg, Young Jun Chang

Department of Physics

Research output: Contribution to journal › Article › peer-review

2 Scopus citations

Abstract

The high-mobility conducting interface (CI) between LaAlO₃ (LAO) and SrTiO₃ (STO) has revealed many fascinating phenomena, including exotic magnetism and superconductivity. But, the formation mechanism of the CI has not been conclusively explained. Here, using in situ angle-resolved photoemission spectroscopy, we elucidated the mechanisms for the CI formation. In as-grown samples, we observed a built-in potential (V_bi) proportional to the polar LAO thickness starting from the first unit cell (UC) with CI formation appearing above 3 UCs. However, we found that the V_bi is removed by synchrotron ultraviolet (UV)-irradiation; The built-in potential is recovered by oxygen gas (O₂(g))-exposure. Furthermore, after UV-irradiation, the CI appears even below 3UC of LAO. Our results demonstrate not only the V_bi-driven CI formation in as-grown LAO/STO, but also a new route to control of the interface state by UV lithographic patterning or other surface modification.

Original language	English
Pages (from-to)	53-57
Number of pages	5
Journal	Current Applied Physics
Volume	30
DOIs	https://doi.org/10.1016/j.cap.2021.04.027
State	Published - Oct 2021

Keywords

Angle-resolved photoemission spectroscopy
Conducting interface
LaAlO
Oxygen vacancy
SrTiO

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@article{b2c7c17659da430c882d5be6a107c444,

title = "In situ investigation of conducting interface formation in LaAlO3/SrTiO3 heterostructure",

abstract = "The high-mobility conducting interface (CI) between LaAlO3 (LAO) and SrTiO3 (STO) has revealed many fascinating phenomena, including exotic magnetism and superconductivity. But, the formation mechanism of the CI has not been conclusively explained. Here, using in situ angle-resolved photoemission spectroscopy, we elucidated the mechanisms for the CI formation. In as-grown samples, we observed a built-in potential (Vbi) proportional to the polar LAO thickness starting from the first unit cell (UC) with CI formation appearing above 3 UCs. However, we found that the Vbi is removed by synchrotron ultraviolet (UV)-irradiation; The built-in potential is recovered by oxygen gas (O2(g))-exposure. Furthermore, after UV-irradiation, the CI appears even below 3UC of LAO. Our results demonstrate not only the Vbi-driven CI formation in as-grown LAO/STO, but also a new route to control of the interface state by UV lithographic patterning or other surface modification.",

keywords = "Angle-resolved photoemission spectroscopy, Conducting interface, LaAlO, Oxygen vacancy, SrTiO",

author = "Yoo, {Hyang Keun} and Luca Moreschini and Aaron Bostwick and Walter, {Andrew L.} and Noh, {Tae Won} and Eli Rotenberg and Chang, {Young Jun}",

note = "Publisher Copyright: {\textcopyright} 2021 Korean Physical Society",

year = "2021",

month = oct,

doi = "10.1016/j.cap.2021.04.027",

language = "English",

volume = "30",

pages = "53--57",

journal = "Current Applied Physics",

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TY - JOUR

T1 - In situ investigation of conducting interface formation in LaAlO3/SrTiO3 heterostructure

AU - Yoo, Hyang Keun

AU - Moreschini, Luca

AU - Bostwick, Aaron

AU - Walter, Andrew L.

AU - Noh, Tae Won

AU - Rotenberg, Eli

AU - Chang, Young Jun

PY - 2021/10

Y1 - 2021/10

N2 - The high-mobility conducting interface (CI) between LaAlO3 (LAO) and SrTiO3 (STO) has revealed many fascinating phenomena, including exotic magnetism and superconductivity. But, the formation mechanism of the CI has not been conclusively explained. Here, using in situ angle-resolved photoemission spectroscopy, we elucidated the mechanisms for the CI formation. In as-grown samples, we observed a built-in potential (Vbi) proportional to the polar LAO thickness starting from the first unit cell (UC) with CI formation appearing above 3 UCs. However, we found that the Vbi is removed by synchrotron ultraviolet (UV)-irradiation; The built-in potential is recovered by oxygen gas (O2(g))-exposure. Furthermore, after UV-irradiation, the CI appears even below 3UC of LAO. Our results demonstrate not only the Vbi-driven CI formation in as-grown LAO/STO, but also a new route to control of the interface state by UV lithographic patterning or other surface modification.

AB - The high-mobility conducting interface (CI) between LaAlO3 (LAO) and SrTiO3 (STO) has revealed many fascinating phenomena, including exotic magnetism and superconductivity. But, the formation mechanism of the CI has not been conclusively explained. Here, using in situ angle-resolved photoemission spectroscopy, we elucidated the mechanisms for the CI formation. In as-grown samples, we observed a built-in potential (Vbi) proportional to the polar LAO thickness starting from the first unit cell (UC) with CI formation appearing above 3 UCs. However, we found that the Vbi is removed by synchrotron ultraviolet (UV)-irradiation; The built-in potential is recovered by oxygen gas (O2(g))-exposure. Furthermore, after UV-irradiation, the CI appears even below 3UC of LAO. Our results demonstrate not only the Vbi-driven CI formation in as-grown LAO/STO, but also a new route to control of the interface state by UV lithographic patterning or other surface modification.

KW - Angle-resolved photoemission spectroscopy

KW - Conducting interface

KW - LaAlO

KW - Oxygen vacancy

KW - SrTiO

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U2 - 10.1016/j.cap.2021.04.027

DO - 10.1016/j.cap.2021.04.027

M3 - Article

AN - SCOPUS:85106317406

SN - 1567-1739

VL - 30

SP - 53

EP - 57

JO - Current Applied Physics

JF - Current Applied Physics

ER -

In situ investigation of conducting interface formation in LaAlO₃/SrTiO₃ heterostructure

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Keywords

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