上海大学材料基因组工程研究院学术报告第七讲：
报告题目：Controllable Complex Oxide Hetero-interfaces （复合氧化物异质界面调控）
报告人：朱英豪 教授（台湾交通大学）
报告时间：2015年1月16日 14：00
报告地点：校本部E408（上海大学材料基因组工程研究院学术报告厅）
报告摘要：
Interfaces have emerged as key focal points of current condensed matter science. In complex correlated oxides, heterointerfaces provide a powerful route to create and manipulate the charge, spin, orbital, and lattice degrees of freedom. The most common interfaces that have been explored are artificially constructed heterointerfaces. The interaction of these degrees of freedom at the heterointerface has resulted in a number of exciting discoveries including the observation of a 2-D electron gas-like behavior at LaAlO3-SrTiO3 interfaces, the emergence of the ferromagnetism in a superconducting material at YBa2Cu3O7-x-La0.7Ca0.3MnO3 interfaces and induced ferromagnetism at BiFeO3La0.7Sr0.3MnO3 interfaces. Among them, the interface of YBa2Cu3O7-x-La0.7Ca0.3MnO3 heterostructures has been intensively studied to understand the proximity effect between ferromagnets and superconductors. One key question has yet to be addressed in this prominent YBa2Cu3O7-x-La0.7Ca0.3MnO3 system: does termination type play an important role in determining the superconducting and magnetic properties? In this talk, we present our studies of YBa2Cu3O7-x-La0.7Ca0.3MnO3 heterostructures with two distinct types of interfacial termination, thus suggesting control of thin film growth at the nanocale. The superconducting and magnetic properties exhibit different responses depending on the type of termination. Based on X-ray scattering, we have found that the magnetic interaction only happens at a particular termination. Cross-sectional scanning tunneling microscopy has been used to study the proximity effect. We found that the competition of superconductor and ferromagnet is different at the two distinct interfaces. Moreover, in the push for practical applications, it is desirable to have the ability to control the interface functionalities by an external stimulus. Therefore we also present our studies of LaAlO3-SrTiO3 interfaces as a model system for controlling functionalities by an external stimulus. Two pathways including non-volatile ferroelectric control and visible-light control of the metal-insulator transition will be demonstrated. These studies open a new avenue to design and engineer new functional oxide interfaces.
报告者简介：
Professor Ying-Hao Chu received his PhD in the Department of Materials Science & Engineering from National Tsing-Hua University in 2004. He joined University of California, Berkeley in 2004 as a postdoc. In 2008 he joined National Chiao Tung University in the Department of Materials Science & Engineering as an assistant professor. In 2013 he started an adjunct position in institute of physics, Academia Sinica. In 2014 he hold an adjunct position in Department of Electrophysics, National Chiao Tung University. His research is highly focused on complex functional oxides and strongly correlated electron systems. He has extensive experience in the use of advanced characterization techniques to understand and manipulate complex functional oxide heterostructures, nanostructures, and interfaces. His current goal is try to create a pathway to use topological defects for next generation electronics. Now, he is top 3 of the most publication in BiFeO3 and top 10 of the most publication in multiferroic materials. He has published more than 180 papers with more than 7300 citations (h-index=44 and i10-index=97) (Web of Science). In 2014, he has been placed in the list of Highly Cited Researchers in Materials Science (Thomson Reuters) (Researcher ID: A-4204-2008).
材料基因组工程研究院
