Anisotropic two-dimensional electron gas at the LaAlO3/SrTiO3 (110) interface
Artikel i vetenskaplig tidskrift, 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.
Författare
A. Annadi
Universiti Kebangsaan Singapura (NUS)
Q. Zhang
Japan Science and Technology Agency
Yancheng Institute of Technology
RIKEN
X. R. Wang
Universiti Kebangsaan Singapura (NUS)
Nikolina Tuzla
Chalmers, Teknisk fysik, Eva Olsson Group
K. Gopinadhan
Universiti Kebangsaan Singapura (NUS)
W. M. Lu
Universiti Kebangsaan Singapura (NUS)
A. R. Barman
Universiti Kebangsaan Singapura (NUS)
Z. Q. Liu
Universiti Kebangsaan Singapura (NUS)
A. Srivastava
Universiti Kebangsaan Singapura (NUS)
S. Saha
Universiti Kebangsaan Singapura (NUS)
Y. L. Zhao
Universiti Kebangsaan Singapura (NUS)
S. W. Zeng
Universiti Kebangsaan Singapura (NUS)
S. Dhar
Universiti Kebangsaan Singapura (NUS)
Eva Olsson
Chalmers, Teknisk fysik, 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
Universiteit Leiden
Universiteit Twente
T. Venkatesan
Universiti Kebangsaan Singapura (NUS)
Ariando
Universiti Kebangsaan Singapura (NUS)
Nature Communications
2041-1723 (ISSN) 20411723 (eISSN)
Vol. 4 1838Ämneskategorier
Annan teknik
DOI
10.1038/ncomms2804