Anisotropic two-dimensional electron gas at the LaAlO3/SrTiO3 (110) interface
Journal article, 2013
The observation of a high-mobility two-dimensional electron gas between two insulating complex oxides, especially LaAlO3/SrTiO3, has enhanced the potential of oxides for electronics. The occurrence of this conductivity is believed to be driven by polarization discontinuity, leading to an electronic reconstruction. In this scenario, the crystal orientation has an important role and no conductivity would be expected, for example, for the interface between LaAlO3 and (110)-oriented SrTiO3, which should not have a polarization discontinuity. Here we report the observation of unexpected conductivity at the LaAlO3/SrTiO3 interface prepared on (110)-oriented SrTiO3, with a LaAlO3-layer thickness-dependent metal-insulator transition. Density functional theory calculation reveals that electronic reconstruction, and thus conductivity, is still possible at this (110) interface by considering the energetically favourable (110) interface structure, that is, buckled TiO2/LaO, in which the polarization discontinuity is still present. The conductivity was further found to be strongly anisotropic along the different crystallographic directions with potential for anisotropic superconductivity and magnetism, leading to possible new physics and applications.
Author
A. Annadi
National University of Singapore (NUS)
Q. Zhang
Japan Science and Technology Agency
Yancheng Institute of Technology
RIKEN
X. R. Wang
National University of Singapore (NUS)
Nikolina Tuzla
Chalmers, Applied Physics, Eva Olsson Group
K. Gopinadhan
National University of Singapore (NUS)
W. M. Lu
National University of Singapore (NUS)
A. R. Barman
National University of Singapore (NUS)
Z. Q. Liu
National University of Singapore (NUS)
A. Srivastava
National University of Singapore (NUS)
S. Saha
National University of Singapore (NUS)
Y. L. Zhao
National University of Singapore (NUS)
S. W. Zeng
National University of Singapore (NUS)
S. Dhar
National University of Singapore (NUS)
Eva Olsson
Chalmers, Applied Physics, Eva Olsson Group
B. Gu
Japan Atomic Energy Agency
Japan Science and Technology Agency
S. Yunoki
RIKEN
Japan Science and Technology Agency
S. Maekawa
Japan Science and Technology Agency
Japan Atomic Energy Agency
H. Hilgenkamp
Leiden University
University of Twente
T. Venkatesan
National University of Singapore (NUS)
Ariando
National University of Singapore (NUS)
Nature Communications
2041-1723 (ISSN) 20411723 (eISSN)
Vol. 4 1838Subject Categories
Other Engineering and Technologies
DOI
10.1038/ncomms2804