Photonic crystals, graphene, and new effects in Čerenkov radiation

by Dr Ido Kaminer (MIT)

Friday 15 Apr 2016, 11:00 → 12:00 Europe/Zurich

40/S2-B01 - Salle Bohr (CERN)

Recent discoveries of new materials, combined with modern nanofabrication techniques, have revealed novel ways of manipulating and confining light on the nanoscale. These developments offer opportunities to control a variety of light-matter interactions, and in particular, manipulate radiation emission from charged particles. In the talk novel phenomena that occur when charged particles interact with photons in such nanophotonic structures will be will discussed. These interactions can lead to novel physical phenomena including a new type of Compton scattering that can be used for compact x-ray sources, and new types of Čerenkov radiation that can potentially improve detectors for high-energy physics experiments. In a conceptual breakthrough that is now more than 80 years old, Čerenkov showed how charged particles emit shockwaves of light when moving faster than the phase velocity of light in a medium. New effects, occurring because of the quantum wave nature of a charged particle, that create unexpected deviations from the conventional Čerenkov theory, have been predicted. Despite the years that have passed since its discovery, and much interest in the Čerenkov effect, it remained inaccessible to most nanoscale electronic and photonic devices because of the relativistic velocities it requires. In a recent project, it could be shown that a newly discovered material called graphene provides the means to overcome this limitation through the low phase velocity of light trapped on its surface. The interaction between the trapped light (called graphene plasmons) and the charge carriers flowing inside graphene presents a highly efficient 2D Čerenkov emission process, giving a versatile, tunable, and ultrafast conversion mechanism from electrical signal to photonic/plasmonic excitation.

Seminar_CERN_April15_2016(4).pdf

Seminar_CERN_April15_2016(4).pptx