Lecturer: Yu Hongyi，Hongkong University
Time: May 16th, 2017, 10:30-11:30 AM, Tue.
Add: 211 Institute of Super Microstructure and Ultrafast Process in Advanced Materials, School of Physics and Electronics, South Campus
Highly uniform and ordered nano dot 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 bodyphysics. Vander Waalshetero structures of 2D semiconductors are naturally endowed with astrictly ordered nanoscale landscape, i.e. themoiré pattern that laterally modulate selectronic and topographic structures. Here we find these moiré effects realize super structures of nanodot confinements for long-lived interlayer excitons, which can be either electrically or strain tuned from perfect arrays of quantum emitters to excitonic super lattices with giant spin-orbit coupling. Besides the wider angetuning of emission wave length, the electric field canal so invert the spin optical selection rule of the emitter arrays. When complex-hopping couples nanodots into honey comb super lattices, the excitonbands feature a Diracnode and two Weylnodes, 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.