Entrada Departamento Notícias Seminário - Supercurrent in a room-temperature Bose-Einstein magnon condensate

Seminário - Supercurrent in a room-temperature Bose-Einstein magnon condensate

13 de setembro de 2016 às 11:00, Anfiteatro -117, FC3 FCUP


Dr. Habil. Alexander A. Serga

Senior scientist

Fachbereich Physik and Landesforschungszentrum OPTIMAS
Technische Universität Kaiserslautern
67663 Kaiserslautern, Germany

 

Abstract:

A supercurrent is a macroscopic effect of a phase-induced collective motion of a quantum condensate. So far, experimentally observed supercurrent phenomena such as superconductivity and superfluidity have been restricted to cryogenic temperatures. Here, I report on the discovery of a supercurrent in a Bose-Einstein magnon condensate prepared in a room-temperature ferrimagnetic film. The magnon condensate is formed in a parametrically pumped magnon gas and is subject to a thermal gradient created by local laser heating of the film. The appearance of the supercurrent, which is driven by a thermally induced phase shift in the condensate wavefunction, is evidenced by analysis of the temporal evolution of the magnon density measured by means of Brillouin light scattering spectroscopy.

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