Local probing of coupled interfaces between two-dimensional electron and hole gases in oxide heterostructures by variable-temperature scanning tunneling spectroscopy

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Abstract

The electronic structure of an epitaxial oxide heterostructure containing two spatially separated two-dimensional conducting sheets, one electronlike (2DEG) and the other holelike (2DHG), has been investigated using variable temperature scanning tunneling spectroscopy. Heterostructures of LaAlO3/SrTiO3 bilayers on (001)-oriented SrTiO3 (STO) substrates provide the unique possibility to study the coupling between subnanometer spaced conducting interfaces. The band gap increases dramatically at low temperatures due to a blocking of the transition from the conduction band of the STO substrate to the top of the valence band of the STO capping layer. This prevents the replenishment of the depleted electrons in the capping layer from the underlying 2DEG and enables charging of the 2DHG by applying a negative sample bias voltage within the band gap region. At low temperatures the 2DHG can be probed separately with the proposed experimental geometry, although the 2DEG is located less than 1 nm below
Original languageEnglish
Article number035140
Pages (from-to)035140-
Number of pages5
JournalPhysical review B: Condensed matter and materials physics
Volume86
Issue number3
DOIs
Publication statusPublished - 2012

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Two dimensional electron gas
Oxides
electron gas
Heterojunctions
Gases
Spectroscopy
Scanning
scanning
oxides
Electrons
Energy gap
gases
spectroscopy
replenishment
conduction
Substrates
Electron transitions
Bias voltage
Valence bands
Conduction bands

Keywords

  • IR-81171
  • METIS-287554

Cite this

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title = "Local probing of coupled interfaces between two-dimensional electron and hole gases in oxide heterostructures by variable-temperature scanning tunneling spectroscopy",
abstract = "The electronic structure of an epitaxial oxide heterostructure containing two spatially separated two-dimensional conducting sheets, one electronlike (2DEG) and the other holelike (2DHG), has been investigated using variable temperature scanning tunneling spectroscopy. Heterostructures of LaAlO3/SrTiO3 bilayers on (001)-oriented SrTiO3 (STO) substrates provide the unique possibility to study the coupling between subnanometer spaced conducting interfaces. The band gap increases dramatically at low temperatures due to a blocking of the transition from the conduction band of the STO substrate to the top of the valence band of the STO capping layer. This prevents the replenishment of the depleted electrons in the capping layer from the underlying 2DEG and enables charging of the 2DHG by applying a negative sample bias voltage within the band gap region. At low temperatures the 2DHG can be probed separately with the proposed experimental geometry, although the 2DEG is located less than 1 nm below",
keywords = "IR-81171, METIS-287554",
author = "Mark Huijben and D. Kockmann and J. Huijben and J.E. Kleibeuker and {van Houselt}, Arie and Gertjan Koster and Blank, {David H.A.} and Hilgenkamp, {Johannes W.M.} and Rijnders, {Augustinus J.H.M.} and Alexander Brinkman and Zandvliet, {Henricus J.W.}",
year = "2012",
doi = "10.1103/PhysRevB.86.035140",
language = "English",
volume = "86",
pages = "035140--",
journal = "Physical review B: Condensed matter and materials physics",
issn = "1098-0121",
publisher = "American Physical Society",
number = "3",

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TY - JOUR

T1 - Local probing of coupled interfaces between two-dimensional electron and hole gases in oxide heterostructures by variable-temperature scanning tunneling spectroscopy

AU - Huijben, Mark

AU - Kockmann, D.

AU - Huijben, J.

AU - Kleibeuker, J.E.

AU - van Houselt, Arie

AU - Koster, Gertjan

AU - Blank, David H.A.

AU - Hilgenkamp, Johannes W.M.

AU - Rijnders, Augustinus J.H.M.

AU - Brinkman, Alexander

AU - Zandvliet, Henricus J.W.

PY - 2012

Y1 - 2012

N2 - The electronic structure of an epitaxial oxide heterostructure containing two spatially separated two-dimensional conducting sheets, one electronlike (2DEG) and the other holelike (2DHG), has been investigated using variable temperature scanning tunneling spectroscopy. Heterostructures of LaAlO3/SrTiO3 bilayers on (001)-oriented SrTiO3 (STO) substrates provide the unique possibility to study the coupling between subnanometer spaced conducting interfaces. The band gap increases dramatically at low temperatures due to a blocking of the transition from the conduction band of the STO substrate to the top of the valence band of the STO capping layer. This prevents the replenishment of the depleted electrons in the capping layer from the underlying 2DEG and enables charging of the 2DHG by applying a negative sample bias voltage within the band gap region. At low temperatures the 2DHG can be probed separately with the proposed experimental geometry, although the 2DEG is located less than 1 nm below

AB - The electronic structure of an epitaxial oxide heterostructure containing two spatially separated two-dimensional conducting sheets, one electronlike (2DEG) and the other holelike (2DHG), has been investigated using variable temperature scanning tunneling spectroscopy. Heterostructures of LaAlO3/SrTiO3 bilayers on (001)-oriented SrTiO3 (STO) substrates provide the unique possibility to study the coupling between subnanometer spaced conducting interfaces. The band gap increases dramatically at low temperatures due to a blocking of the transition from the conduction band of the STO substrate to the top of the valence band of the STO capping layer. This prevents the replenishment of the depleted electrons in the capping layer from the underlying 2DEG and enables charging of the 2DHG by applying a negative sample bias voltage within the band gap region. At low temperatures the 2DHG can be probed separately with the proposed experimental geometry, although the 2DEG is located less than 1 nm below

KW - IR-81171

KW - METIS-287554

U2 - 10.1103/PhysRevB.86.035140

DO - 10.1103/PhysRevB.86.035140

M3 - Article

VL - 86

SP - 035140-

JO - Physical review B: Condensed matter and materials physics

JF - Physical review B: Condensed matter and materials physics

SN - 1098-0121

IS - 3

M1 - 035140

ER -