Anisotropic two-dimensional electron gas at the LaAlO/SrTiO (110) interface

LaAlO/SrTiO (110)接触面における異方性2次元電子ガス

Annadi, A.*; Zhang, Q.*; Renshaw Wang, X.*; Tuzla, N.*; Gopinadhan, K.*; L, W. M.*; Roy Barman, A.*; Liu, Z. Q.*; Srivastava, A.*; Saha, S.*; Zhao, Y. L.*; Zeng, S. W.*; Dhar, S.*; Olsson, E.*; Gu, B.; 柚木 清司*; 前川 禎通; Hilgenkamp, H.*; Venkatesan, T.*; Ariando*

Annadi, A.*; Zhang, Q.*; Renshaw Wang, X.*; Tuzla, N.*; Gopinadhan, K.*; L, W. M.*; Roy Barman, A.*; Liu, Z. Q.*; Srivastava, A.*; Saha, S.*; Zhao, Y. L.*; Zeng, S. W.*; Dhar, S.*; Olsson, E.*; Gu, B.; Yunoki, Seiji*; Maekawa, Sadamichi; Hilgenkamp, H.*; Venkatesan, T.*; Ariando*

We report the observation of unexpected conductivity at the LaAlO/SrTiO interface prepared on (110)-oriented SrTiO, with a LaAlO-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 TiO/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.