Day / Time
Date(s) - 31/03/2014
17 h 00 min - 18 h 30 min
Ecole de Physique, Auditoire Stueckelberg, 24 quai E. Ansermet
The colloquia « Nano-plasmonic phenomena in graphene » will be presented by Dimitri N. Basov, University of California, San Diego.
The term “plasmonics” often carries an applied connotation owing to remarkable successes in controlling and manipulating light at the nanoscale in artificial structures. Infrared nano-spectroscopy and nano-imaging experiments on graphene carried out in our group [Nano Letters 11, 4701 (2011), Nature Nanotechnology (2013)] have uncovered a rich variety of plasmonic effects that may enable functionalities not attainable through metal-based plasmonics. Applications aside, the nano-scale exploration of surface plasmons has offered an entirely new perspective on fundamental physics behind electronic phenomena in graphene. For example, by direct infrared imaging of plasmonic standing waves we were able to quantify the electronic losses in graphene [Nature 487, 82 (2012)]. This latter result highlights the important role of many body effects that were not anticipated theoretically. By examining the sub picosecond dynamics of plasmons in a setting of a unique pump-probe nano-spectroscopy apparatus we were able to discriminate between the roles of several photo-induced processes in mono-layer and few layer graphene [under review]. Remarkably, infrared photo-excitation enables ultra-fast control of plasmons with the efficiency rivaling that of electrostatic gating.