报告人简介

谢微，华东师范大学物理与材料科学学院研究员。2002—2006年，上海大学物理系本科；2007—2012年，复旦大学物理系博士研究生；2012—2014年，复旦大学物理系助理研究员；2014—2015年，美国密西根州立大学光学博士后，2015年10月始在华东师范大学工作。在Phys. Rev. Lett., PNAS, Optica, Phys. Rev. B等期刊发表论文30余篇，主要研究固态环境中光-物质相互作用及其调控，包括以下子方向：微纳光学结构中的量子行为及调控，低维及界面体系的光谱特征，半导体中激子等准粒子的光电特性。

报告摘要

Phase correlations of quasi-/particles attract long-standing research efforts due to the close relation with many-body behaviors and macroscopic cooperative phenomena. Based on the long-range phase correlation of exciton-polaritons in semiconductor microcavity systems, a variety of macroscopic quantum behaviors are revealed, such as polaritonic BEC, superuid, vortex, etc. Polariton condensate can be formed at the ground state of its resonant modes through final state stimulation scattering. However, is it possible to realize polariton condensate by evaporative cooling like BEC in the atom gas system? In the first part of this talk, we will demonstrate that, when some defects are introduced into a 1D ZnO microcavity, trap potentials for polariton condensate can be created. An efficient cooling is achieved in this polariton-trapped system with the effective temperature of polariton gas reducing to about 20 K in the room temperature experiments. The condensate component reaches nearly 50% in this 3D-confined system of strong polariton-polariton interaction. In the second part of the talk, we will pay attention to the controlling of condenate’s state. The condensation behavior of polariton usually takes place at the ground state of the system with momentum k=0. Could it is possible to manipulate the state at which bosons will accumulate and to realize massive occupation of polaritons only at certain excited state with non-zero momentum? Interestingly, we observe the condensate at the edge of the Brillouin zone in a polaritonic crystal. This peculiar condensation is governed by the lifetime variation of polariton states in the additional periodic potential.