title: Dynamics and spontaneous coherence of magnons in ferromagnetic thin films.
abstract: A theory of the dynamics of the Bose-Einstein condensate of magnons is presented. It is shown that, despite magnon decay processes, ongoing during the condensate formation, the system manifests spontaneous quantum coherence with a pseudo-spin degree of freedom originated from the presence of two valleys in momentum space. Finally, a real space description of the condensed state is provided, revealing the condensate state as a spin density wave. The effective dynamics of the spinor condensate wavefunction is characterized, and it is shown to display Josephson-like relations.
authors.affiliation: Departamento de Física, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago, Chile.
authors.forename: Roberto E
authors.initials: RE
authors.lastname: Troncoso
authors.forename: Alvaro S
authors.initials: AS
authors.lastname: Núñez