Date(s) - 21/03/2018
3:30 pm - 4:30 pm
Title: Polaritonsin van der Waals materials: insights from near field nano-optics
Speaker: Dr. Dmitri Basov
Institute: Columbia University
Description: In 1944 Hans Bethe reported on “the diffraction of electromagnetic radiation by a hole small compared with the wave-length” [Physical Review 66, 163 (1944)]. This seminal paper was among the early precursors to a new and vibrant area of research: near field nano-optics. I will discuss recent nano-optical experiments on van der Waals materials including: graphene and transition metal dichaloco genides. Central to the nano-optical exploration of quantum materials is the notion of polaritons: hybrid light matter modes that are omnipresent in polarizable media. Infrarednano-optics allows one to directly image polaritonic standing waves [Science343, 1125 (2014), Nature Materials 14, 1217 (2015)] yielding rich insights into the electronic phenomena of the host material supporting polaritons [Science 354,195 (2016)]. I will give a progress report on the search for the role of the Berry phase in the properties of graphene via transient polaritonic imaging [NaturePhotonics 10, 244 (2016); Nature Materials 16, 1077 (2017)].