Journal Club do Departamento de Física dos Materiais e Mecânica do IFUSP
Nesta semana o pós-graduando Alysson Ferreira Morais apresentará o artigo:
"Real-space Collapse of a Polariton Condensate"
L. Dominici et al Nature Communications 6 9993 (2015)
link: http://www.nature.com/ncomms/2015/151204/ncomms9993/abs/ncomms9993.html
Microcavity polaritons are two-dimensional bosonic fluids with strong nonlinearities, composed of coupled photonic and electronic excitations. In their condensed form, they display quantum hydrodynamic features similar to atomic BoseEinstein condensates, such as long-range coherence, superfluidity and quantized vorticity. Here we report the unique phenomenology that is observed when a pulse of light impacts the polariton vacuum: the fluid which is suddenly created does not splash but instead coheres into a very bright spot. The real-space collapse into a sharp peak is at odd with the repulsive interactions of polaritons and their positive mass, suggesting that an unconventional mechanism is at play. Our modelling devises a possible explanation in the self-trapping due to a local heating of the crystal lattice, that can be described as a collective polaron formed by a polariton condensate. These observations hint at the polariton fluid dynamics in conditions of extreme inten!
sities and ultrafast times.
Data: 01 de março de 2016 (terça-feira)
Horário: às 12h10min
Local: Sala de Seminários José Roberto Leite - Ed. Alessandro Volta (bloco C) - sala 110
