A defining characteristic of complex transition-metal oxides (TMOs) is their vast variety of physical properties, emerging from a complicated competition between multiple energy scales and the close coupling with charge, spin, and lattice degrees of freedom. The chemical and physical complexity, though presenting a formidable challenge in condensed matter physics, offer a fabulous playground for making artificial structures of these materials with new quantum physics of matter.
In this talk, I will introduce our ability in growing high quality thin films with atomically sharp interfaces, as well as powerful tools to characterize their properties down to atomic scale, which allow us to explore unconventional interfaces and search for novel quantum functionality. I will discuss that broken symmetry at interface results in many exciting emergent phenomena: 1) spontaneous magnetization reversal and inverted hysteresis persisting well above room temperature at the interface of La2/3Sr1/3MnO3 (LSMO)/SrTiO3; 2) interface-induced magnetic polar metal phase in BaTiO3/SrRuO3/BaTiO3 (BTO) heterostructure; and 3) Interface-induced multiferroism in BTO/LSMO superlattices. These exciting new properties are closely related to the dramatic modification of structure/chemistry at the interface. Our results open up a conceptually intriguing recipe for developing novel functional ultrathin materials via interface-induced charge-spin-lattice coupling.

*Supported by US U.S. DOE under Grant No. DOE DE-SC0002136 as well as NSF under Grant No. NSF DMR-1608865.

Bio： Prof. Jiandi Zhang received B.S. and M.S. degrees in physics from the Nanjing University of Science and Technology in 1982 and the Chinese Academy of Science (CAS) in 1986, respectively. Then he was on the faculty of Shanghai Jiao Tong University between 1986 and 1989. He received his Ph.D. degree in physics from Syracuse University in 1994, spent about one year at University of Nebraska-Lincoln and 3 years as a postdoc fellow at Oak Ridge National laboratory/the University of Tennessee prior to joining the Florida International University as a faculty member in 1998. Starting from 2009, he became a full professor in physics at Louisiana State University. He is also a visiting professor at CAS since 2007. He has published more than 120 peer-reviewed research articles. He is a fellow of American Physical Society.
Detailed about Zhang’s research group can found at http://www.phys.lsu.edu/material-physics/