Two-Dimensional Electron Gas with High Mobility Forming at BaO/SrTiO_(3) Interface  

作　　者：Cheng Cao Shengru Chen Jun Deng Gang Li Qinghua Zhang Lin Gu Tian-Ping Ying Er-Jia Guo Jian-Gang Guo Xiaolong Chen 曹程;陈盛如;邓俊;李岗;张庆华;谷林;应天平;郭尔佳;郭建刚;陈小龙(Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 101408,China;College of Materials Science and Opto-Electronic Technology,University of Chinese Academy of Sciences,Beijing 100049,China;Songshan Lake Materials Laboratory,Dongguan 523808,China)

机构地区：[1]Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China [2]School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 101408,China [3]College of Materials Science and Opto-Electronic Technology,University of Chinese Academy of Sciences,Beijing 100049,China [4]Songshan Lake Materials Laboratory,Dongguan 523808,China

出　　处：《Chinese Physics Letters》2022年第4期41-46,共6页中国物理快报（英文版）

基　　金：financially supported by the Mo ST-Strategic International Cooperation in Science,Technology and Innovation Key Program(Grant No.2018YFE0202600);the National Key Research and Development Program of China(Grant Nos.2017YFA0304700 and 2020YFA0309100);the National Natural Science Foundation of China(Grant Nos.51922105,51532010,and 11974390);the Beijing Natural Science Foundation(Grant Nos.Z200005,Z190010,and 2202060);the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB33030200);the Beijing Nova Program of Science and Technology(Grant No.Z191100001119112)。

摘　　要：Two-dimensional electron gas(2DEG)with high electron mobility is highly desired to study the emergent properties and to enhance future device performance.Here we report the formation of 2DEG with high mobility at the interface between rock-salt Ba O and perovskite Sr Ti O_(3).The interface consists of the ionically compensated Ba O_(1-δ) layer and the electronically compensated Ti O_(2) layer,which is demonstrated as a perfect interface without lattice mismatch.The so-formed interface features metallic conductivity with ultralow square resistance of7.3×10^(-4)Ω/□at 2 K and high residual resistance ratios R_(300 K)/R_(2 K) up to 4200.The electron mobility reaches69000 cm^(2)·V^(-1)·s^(-1)at 2 K,leading to Shubnikov–de Haas oscillations of resistance.Density functional theory calculations reveal that the effective charge transfers from Ba O to the Ti 3d_(xy) orbital occur at the interface,leading to the conducting Ti O_(2) layer.Our work unravels that Ba O can adapt itself by removing oxygen to minimize the lattice mismatch and to provide substantial carriers to Sr Ti O_(3),which is the key to forming 2DEGs with high mobility at the interfaces.

关 键 词：INTERFACE ELECTRON RESISTANCE 

分 类 号：TQ117[化学工程—无机化工] O469[理学—凝聚态物理]