Por Hugo Terças (Departamento de Física do Instituto Superior de Engenharia de Lisboa, Instituto Politécnico de Lisboa; and Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Portugal).

Kinetic theory is arguably one of the most valuable tools for addressing out-of-equilibrium phenomena in condensed matter. In hard condensed matter, a notable application of kinetic theory in the quantum realm is quantum plasmonics in graphene and other Dirac materials. This advancement has fostered the development of nanodevices that serve as both emitters and detectors, finding applications in various fields, particularly in the THz range. While the hydrodynamic regime of carriers in bidimensional Dirac materials has been comprehensively addressed through both analytical and computational methods, the kinetic aspects remain relatively unexplored. Most kinetic equations employed in this context primarily focus on the dynamics of electrons and holes, neglecting the effects of excitations. In this study, we propose a kinetic theory for a third species (plasmons) to perform a one-loop correction to the quantum kinetic theories of Dirac materials. One intriguing consequence of this approach is the emergence of “second sound” modes and the collapse of plasma waves. In soft condensed matter, kinetic theory holds significant importance in the dynamics of colloids. We demonstrate that simulation of mean-field kinetic equations can qualitatively reproduce the coagulation dynamics of colloids. Furthermore, we show that thermal effects can be effectively addressed as an initial value problem of the Landau type, akin to plasma physics.