Miguel I. Berganza - IPCF-CNR Roma #
The laser as a collective phase #
We will review the statistical physics approach to the nonlinear interaction of 
electromagnetic modes in lasers. Within this approach, the mode-locking of lasers can 
be understood as a phase transition in the canonical ensemble, where the role of the 
temperature is played by the spontaneous emission. When applied to the random laser 
phenomenon, in which the randomness on the spatial position of the scatterers induces 
a frustration in the mode interaction, this approach contemplates a glassy phase with 
nonvanishing complexity for large enough disorder. In this context, we will present 
some novel results regarding the collective phases of vector spin models with 
four-body interactions, and their numerical analysis.