LaAlO3/SrTiO3和NdGaO3/SrTiO3氧化物异质界面二维电子气导电物理机制研究

项目名称： LaAlO3/SrTiO3和NdGaO3/SrTiO3氧化物异质界面二维电子气导电物理机制研究

项目编号： No.51302132

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 一般工业技术

项目作者： 谢琳

作者单位： 南京大学

项目金额： 20万元

中文摘要： 近年来，人们在LaTiO3/SrTiO3和LaAlO3/SrTiO3等绝缘体氧化物异质界面体系中发现界面导电，也即二维电子气现象，这激发了学术界和工业界对绝缘体氧化物异质界面的绝缘-金属转变、导电等一系列新奇物理现象及机制的研究热潮。目前，学术界对界面处二维电子气产生的物理机制仍存在各种争议，且其产生机制与界面的具体成分和结构有关。本项目申请计划采用先进像差校正电子显微镜技术以及原位电子显微技术对典型氧化物异质界面的原子和电子结构进行研究，并阐明不同物理机制对异质界面处二维电子气的影响。

中文关键词： 氧化物异质界面；二维电子气；绝缘体-金属转变；像差校正透射电子显微术；第一性原理计算

英文摘要： In recent years, it was found in insulating oxide heterostructure interface, e.g. LaTiO3/SrTiO3 and LaAlO3/SrTiO3, that the material is conducting in the interface region. The finding of this so-called two-dimensional electron gas enthusiates the wide research of insulator-metal transition, interface conducting and related novel physical phenomena and mechanisms in insulating oxide heterostructure both in academia and industry. By now, the mechanism of two-dimensional electron gas in oxide heterostructure is still in controversy and it was well accepted that the mechanism is closely related to the composition and structure of the interface. In this proposal, we plan to investigate the atomic and electronic structure of representative oxide heterostructure interface by combining the advanced aberration-corrected transmission electron microscopy and in-situ electron microscopy. Based on these results, different mechanisms and model explaining the formation of two-dimensional electron gas are also discussed.

英文关键词： oxide heterostructure interface；two-dimensional electron gas；insulator-metal transition；aberration-corrected electron microscopy；first-principles calculation