题　目：Novel pseudospin-mediated phenomena in photonic graphene
报告人：陈志刚 教授（Department of Physics and Astronomy, San Francisco State University）
时　间：11月9日（周一），下午1:30-3:00
地　点：物理馆502会议室

Abstract（报告摘要）:

Pseudospin, an additional degree of freedom inherent in graphene, plays a key role inunderstanding many fundamental phenomena such as the anomalous quantum Hall effect,electron chirality and Klein paradox. Unlike the electron spin, the pseudospin was traditionallyconsidered as an unmeasurable quantity, immune to Stern-Gerlach-type experiments.Recently, however, it has been suggested that graphene pseudospin is a real angularmomentum that might manifest itself as an observable quantity, but so far direct tests of sucha momentum remained unfruitful. In this talk, we will discusshow to realize pseudospin-mediated vortex generation andtopological charge flipping in otherwise uniform optical beams with Bloch momentumtraversing through the Dirac points,by selective excitation of two sublattices of anartificial photonic grapheme.We show that pseudospin can turn into orbital angularmomentum completely, thus upholding the belief that pseudospin is not merely fortheoretical elegance but rather physically measurable.

Brief Biography（个人简介）:

Dr. Chen earned his Ph.D. from Bryn Mawr College in 1995. After two years of postdoctoral work, he was promoted to the rank of Senior Research Staff Member at Princeton University before joining the faculty at San Francisco State University in 1998. He has edited a book and published 8 invited book chapters, along with over 300 scientific papers in top-rated refereed journals and conference proceedings, including Science, Science Advances, Nature Materials, Nature Communications, and Proceedings of the National Academy of Sciences. He is a Fellow of the OSA, a Fellow of the APS, and an Editor for Optics Letters, Scientific Reports, and Science Bulletin.

Research Interest（研究方向）:

Nonlinear Optics and Photonics, Optical Trapping and Manipulation, BioPhotonics, Soft Condensed Matter, Photonic Materials, Spatial Solitons and Waveguides.