报告题目：Programmable quantum emitter arrays and spin-orbit coupled superlattices of Moiré excitons
报告人：Hongyi Yu （The University of Hong Kong）
报告时间：2017年5月18日（周四）下午3:00pm
报告地点：物理学院新楼大报告厅503
Abstract:
Highly uniform and ordered nanodot arrays are crucial for high performance quantum optoelectronics including new semiconductor lasers and single photon emitters, and for synthesizing artificial lattices of interacting quasiparticles towards quantum information processing and simulation of many-body physics. Van der Waals heterostructures of 2D semiconductors are naturally endowed with a strictly ordered nanoscale landscape, i.e. the moiré pattern that laterally modulates electronic and topographic structures. Here we find these moiré effects realize superstructures of nanodot confinements for long-lived interlayer excitons, which can be either electrically or strain tuned from perfect arrays of quantum emitters to excitonic superlattices with giant spin-orbit coupling. Besides the wide range tuning of emission wavelength, the electric field can also invert the spin optical selection rule of the emitter arrays. When complex-hopping couples nanodots into honeycomb superlattices, the exciton bands feature a Dirac node and two Weyl nodes, connected by spin-momentum locked topological edge modes. With the observed long lifetime and spin dependent interaction, these moiré excitons provide an exciting Bose-Hubbard system with versatile controllability for exploring exotic quantum phases.
Biosketch:
Dr. Hongyi Yu obtained a B.S from Peking University in 2004. He went to the Institute of Physics, Chinese Academy of Sciences for graduate studies, and received his Ph.D in condensed matter physics in 2010. He then joined Prof. Wang Yao’s group in the University of Hong Kong as a postdoctoral scholar, then a research assistant professor since 2016. His recent research was focused on the valley and spin physics in 2D layered semiconductors, and has yield many important works including 2 Nat. Phys., 1 Nat. Nanotechnol, 3 PRL, 2 Science and 3 Nat. Commun. et.al..
邀请人：张晨栋教授
