报告时间：6月5日 下午2：00
报告地点：唐仲英楼 B305
报告题目：A novel artificial condensed matter lattice and a new platform for one-dimensional topological phases
摘要：We are always searching for new ways to manipulate and engineer materials. To change the properties of a crystal, we can use strategies like chemical doping, applying pressure, changing the temperature or varying the thickness of a film. We also have clever ways to engineer band structures from the ground up in cold-atom optical lattices or photonic crystals. In this talk, I will demonstrate a new scheme to engineer band structures, using topological insulators. We use molecular beam epitaxy (MBE) to stack thin films of trivial and topological insulators in an alternating pattern to form a multilayer heterostructure. Each interface hosts topological interface states. By making each layer < 7nm thick, we allow quantum tunneling between nearby interfaces. In this way, we form an emergent, tunable superlattice band structure where each interface acts as a lattice site and each topological interface state acts as an atomic orbital. After introducing the basic concept, I will present data from angle-resolved photoemission spectroscopy (ARPES) demonstrating an emergent electronic band structure. I will also discuss how we might use this scheme to realize novel topological invariants in both 3D and 1D, as well as other neat applications.
Reference: Belopolski et al., Sci. Adv., e1501692 (2017).
报告人简介：Belopolski博士主要从事凝聚态物理方向的研究，研究方向包括量子电子系统的异常突发现象研究以及其技术应用；拓扑绝缘体，半金属以及超导体的理论预测，材料搜索以及拓扑态的实验实现；量子霍尔效应，Kondo绝缘体以及超导体的强相互作用电子相的研究；Weyl费米子，Majorana费米子等晶体中新出现粒子的研究；自旋电子学，量子输运以及量子计算等拓扑态的应用研究。发表文章包括Science, Nature physics, Nature Materials, Nature Communication, PRL等。
