报告题目:Interface-Driven Quantum Magnetism in Oxide Heterostructures

报  告  人:Jiandi Zhang, Department of Physics and Astronomy, Louisiana State University

报告时间:2018-07-10 16:00

报告地点:物理系理科楼B315

报告摘要: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.