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

RIKEN

Yancheng Institute of Technology

Japan Science and Technology Agency

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 Science and Technology Agency

Japan Atomic Energy Agency

S. Yunoki

RIKEN

Japan Science and Technology Agency

S. Maekawa

Japan Atomic Energy Agency

Japan Science and Technology Agency

H. Hilgenkamp

Universiteit Leiden

Universiteit Twente

T. Venkatesan

Universiti Kebangsaan Singapura (NUS)

Ariando

Universiti Kebangsaan Singapura (NUS)

Nature Communications

2041-1723 (ISSN)

Vol. 4

Ämneskategorier

Annan teknik

DOI

10.1038/ncomms2804