物理系学术报告       Physics Department Colloquium

 

1214周五16:00-17:0012-201

 

 

 

Excitonic Polaritons in ZnO Microcavity

 

陈张海

复旦大学 

 

  

 

Exciton-polariton is a quasi-particle formed by the coupling of photon and exciton in solid-state environment. One of the most important systems for realizing polariton in a strong coupling regime is semiconductor microcavity, in which the optical cavity modes can be tailored or tuned to resonant in energies with excitons. Recently, polariton behavior in cavities with reduced dimensionality is attracting more attention, since it is expected that the reduced dimensionality will greatly lift the wave vector conservation selection rules in polariton scattering, and it is an effective way to realize polariton quantum degeneracy under nonresonant pumping. On the other hand, as one of the most commonly adopted cavity types for photon confinement, a whispering gallery (WG) resonator where photons are confined two-dimensionally has indeed its advantage for the light-matter interaction studies. The overlap between exciton and cavity mode is greatly enhanced and can be close to unity due to the body of WG microcavity is itself an active medium for excitonic emission. However, despite the above advantages, polariton behavior in WG cavities is less understood, though it is of fundamental importance. Moreover, tunability in both exciton-photon coupling strength and emission wavelength of a polariton laser out of a planar cavity remains difficult.

In this talk, I will demonstrate a tunable WG resonator for polaritons basing on a ZnO nano-rod with a hexagonal cross-section. Comprehensive polariton behaviors, including the one-dimensional polariton dispersion, polariton condensate, polariton nonlinear parametric scattering, and polariton propagation are discussed. Our work demonstrates that ZnO WG microcavity is an excellent system for developing polariton-based devices operated at room temperature.




陈张海教授简介:

陈张海教授于1991年和1994年在厦门大学获得学士和硕士学位,1997年在中国科学院上海技术物理研究所获得博士学位。随后在澳大利亚国立大学电子材料工程系访问学者,日本东北大学多元物质科学研究所博士后。2003年起任复旦大学物理系教授、博士生导师。2006年-2011年任复旦大学应用表面物理国家重点实验室副主任,2010年起任复旦大学物理系副主任。2009年受聘日本东京大学客员教授,曾经获得国家自然科学杰出青年基金资助和中国物理学会黄昆物理奖。

主要从事半导体小量子体系中电子态、光子-电子相互作用的物理研究。近期的研究兴趣包括:半导体光学微腔中的激子极化激元和固体环境中类氢原子电子态的量子混沌动力学。