Stability and electronic structure studies of LaAlO_3/SrTiO_3 (110) heterostructures  

作　　者：杜颜伶 王春雷 李吉超 徐攀攀 张新华 刘剑 苏文斌 梅良模 

机构地区：[1]School of Physics, State Key Laboratory of Crystal Materials, Shandong University [2]College of Science and Technology, Shandong University of Traditional Chinese Medicine

出　　处：《Chinese Physics B》2014年第8期468-473,共6页中国物理B（英文版）

基　　金：Project supported by the National Basis Research Program of China(Grant No.2013CB632506);the National Natural Science Foundation of China(Grant Nos.11374186,51231007,and 51202132);the Independent Innovation Foundation of Shandong University,China(Grant No.2012TS027)

摘　　要：The first-principles calculations are employed to investigate the stability, magnetic, and electrical properties of the oxide heterostructure of LaAIO3/SrTiO3 （110）. By comparing their interface energies, it is obtained that the buckled interface is more stable than the abrupt interface. This result is consistent with experimental observation. At the interface of LaAIO3/SrTiO3 （110） heterostructure, the Ti-O octahedron distortions cause the Ti tzg orbitals to split into the two- fold degenerate dxz/dyz and nondegenerate dxy orbitals. The former has higher energy than the latter. The partly filled two-fold degenerate t2g orbitals are the origin of two-dimensional electron gas, which is confined at the interface. Lattice mismatch between LaA103 and SrTiO3 leads to ferroelectric-like lattice distortions at the interface, and this is the origin of spin-splitting of Ti 3d electrons. Hence the magnetism appears at the interface of LaAIO3/SrTiO3 （110）.The first-principles calculations are employed to investigate the stability, magnetic, and electrical properties of the oxide heterostructure of LaAIO3/SrTiO3 （110）. By comparing their interface energies, it is obtained that the buckled interface is more stable than the abrupt interface. This result is consistent with experimental observation. At the interface of LaAIO3/SrTiO3 （110） heterostructure, the Ti-O octahedron distortions cause the Ti tzg orbitals to split into the two- fold degenerate dxz/dyz and nondegenerate dxy orbitals. The former has higher energy than the latter. The partly filled two-fold degenerate t2g orbitals are the origin of two-dimensional electron gas, which is confined at the interface. Lattice mismatch between LaA103 and SrTiO3 leads to ferroelectric-like lattice distortions at the interface, and this is the origin of spin-splitting of Ti 3d electrons. Hence the magnetism appears at the interface of LaAIO3/SrTiO3 （110）.

关 键 词：two-dimensional electron gas LaAIO3/SrTiO3 （110） interface magnetic interface 

分 类 号：O562[理学—原子与分子物理]