When:
Monday, March 28, 2016
3:00 PM - 4:00 PM CT
Where: Technological Institute, F210, 2145 Sheridan Road, Evanston, IL 60208 map it
Audience: Faculty/Staff - Student - Public
Contact:
Liz Lwanga
(847) 491-3645
Group: Physics and Astronomy Condensed Matter Physics Seminars
Category: Academic
Title: Coherent excitation of a "magnonic sound"
Speaker: A. Slavn, University of Muenster
Abstract: We report experiment on coherent excitation of sound-like waves in a dense gas of strongly interacting quasiparticles - parametrically pumped microwave magnons undergoing Bose-Einstein condensation (BEC) at room temperature . At low wavenumbers the discovered “magnonic sound” shows a linear dispersion, which becomes almost quadratic above a certain characteristic wavenumber proportional to the magnon density. The "magnonic sound" is dissipative in a sense that the real and imaginary parts of its wavenumber are comparable. The observed excitation of sound-like waves finds an explanation within a classical Boltzmann theory modified for the case of a quasi-equilibrium gas of magnon quasiparticles.
Keywords: Physics, Astronomy, CMP