论文部分内容阅读
The field of Statistical Physics provides many different tools,which are based either on microscopic approaches or on a more phenomenological level to describe the spread of heat in classical and quantum regimes in realistic and more idealized model systems of arbitrary dimensions.Typical such powerful tools are first principles Linear Response Theory for transport coefficients,yielding the celebrated Green-Kubo formulas,the stochastic theory of Random Walks,or mesoscopic approaches such as the more practical treatments in terms of kinetic transport equations.In low dimensional systems the transport of heat in form of diffusive spread or heat flux between reservoirs of differing ambient temperatures typically may exhibit anomalous features such as the violation of the Fourier Law with length-dependent heat conductivities or the diffusive spread of heat that occurs faster than normal.In this talk we discuss recent results how the dynamics of energy spread occurring in one-dimensional nonlinear lattices relates to anomalous diffusion behavior and heat conductivities.Moreover we explain how the carriers of heat,typically referred to as phonons,may be given meaning in a regime with nonlinear interaction forces beyond the ballistic behavior originating from solely present harmonic(linear)interaction forces.The underlying physical mechanism of scattering then renders corresponding mean free paths of such effective phonons finite.