题目：Raman spectroscopy of two-dimensionalmaterials

报告人：Riichiro Saito

Department of Physics, Tohoku University

地点： 教十二-201

时间： 3月22日，周五，14:00-15:00

Abstract

We overview our recenttheoretical activity on Raman spectroscopy of two-dimensional materials. Ramanscattering is an inelastic scattering of light. Raman spectroscopy isfrequently observed for characterizing the structure of emergingtwo-dimensional materials such as graphene, transition metal dichalcogenides.When we change the laser excitation energy for observing the Raman spectra, theRaman intensity significantly changes due to the resonant Raman effect.Combining with our original computer program for resonant Raman intensity, wecan understand many properties from Raman spectra of the recent two-dimensionalmaterials. In particular, when we use circularly polarized light, we get somespecial Raman spectra appears in which the inelastic scattered light has an oppositehelicity of the circularly polarized light to that of the incident light, whichwe can explain by the symmetry analysis. Here we will discuss on conservationlaw of angular momentum of a photon in the Raman processes. When we discussoptical properties of two-dimensional materials, the concepts of valleypolarization and circular dichroism are important, which we will discusspossible phenomena that occur in two-dimensional materials

Short Biography

Riichiro Saito was born in 1958, and received his Ph. D. at TheUniversity of Tokyo in 1985. He becameResearch Associate at The University of Tokyo (1985), Associate Professor atThe University of Electro-Communications (1990), and Professor at Department ofPhysics, Tohoku University (2003). Hehas been a visiting scientist at Massachusetts Institute of Technology (1991-2)at Prof. Gene Dresselhaus and Prof. Mildred S. Dresselhaus, Visiting AssociateProfessor at The University of Tokyo (1990-1, 1993-4, 1997-8), VisitingProfessor at Shanghai University (2009.10-2011.10) and Zhejiang University(2018.12-).

His main field of research is “Physical Properties of Carbon Nanotubes”and “Raman spectroscopy in Graphite Related Systems”. The books with the sametitles published, respectively, from Imperial College Press (1998) (CI = 9634)with Prof. Gene Dresselhaus and Prof. Mildred S. Dresselhaus and from Wiley-VCHwith Prof. A. Jorio, Prof. Gene Dresselhaus and Prof. Mildred S. Dresselhaus.Recently he is interested in optical properties of two dimensional materials.He got 13th Japan IBM prize (Physics, 1999), Hsun Lee research Award (2006),The Japan Carbon Award for Innovation Research (2008). Somiya Award,International Union of Materials Research Societies (2009).

He has published 329 original papers with total citation is 31,276 (averagecitation per article = 95.06, h-index=80). 62 papers are more than 100citations and among them 28 papers are more than 200. Google scholar citationindex is 56,902.