Lien Zoom: https://umontreal.zoom.us/j/93026432919
Meeting ID: 930 2643 2919
Passcode: écrire en chiffre: un, trois, sept.
First presentation:
Ultrafast energy flow across the Brillouin zone in two-dimensional materials
Laurent René de Cotret
Physics Department
McGill University
Présentation en anglais
Abstract: In this talk I will show you how to extend ultrafast electron diffraction measurements to directly access ultrafast phonon dynamics in two-dimensional materials. Ultrafast electron scattering will be introduced, with special emphasis on the key advancement of RF-compression of electron bunches. Then, three experiments will be presented. First, time- and momentum-dependent phonon population dynamics in photoexcited graphite will be used to extract electron- and phonon-phonon coupling values across the Brillouin zone. Second, the source of anharmonicity in a high-efficiency thermoelectric material will be discussed via observations of ultrafast phonon renormalization. Finally, if time permits, the phonon dynamics of photoexcited 1T-TiSe2 will be used to infer some properties of the charge-density wave phase.
Second presentation:
To slipstream terahertz pulses
Aidan Schiff-Kearn
Physics Department
McGill University
Présentation en anglais
Abstract: The ability to use light moves in lockstep with the ability to control it. In this talk, I will present our latest efforts in tailoring terahertz pulses using our parallel plate waveguide platform. Through interactions with a moving relativistic front created by photoexcitation, we demonstrate two exotic photonic operations in the terahertz range: temporal stretching and time-reversal of a terahertz pulse.
Cette conférence est présentée par le RQMP.
