1 University G. Marconi of Rome, Dermatology and Venereology, Rome 00192, Italy; 2 Medical Institute of the Ministry of Interior, Dermatology, Venereology and Dermatologic Surgery; Onkoderma, Private Clinic for Dermatologic Surgery, Dermatology and Surgery, Sofia 1407, Bulgaria; 3 Krankenhaus Dresden-Friedrichstadt, Department of Dermatology and Venereology, Dresden, Sachsen, Germany; 4 Univers...

The third-order optical response function of a chromophore coupled to a bath consisting of noninteracting two-level systems (TLSs) undergoing stochastic jumps is calculated. The results can be applied to a broad class of nonlinear optical techniques in single-molecule spectroscopy and bulk measurements in glasses, polymers, and mixed crystals. In the limit of many TLSs weakly coupled to the chr...

A general formulation is developed to study heat conduction in disordered harmonic chains with arbitrary heat baths, satisfying the fluctuation-dissipation theorem. A simple formal expression for the heat current J is obtained, from which its asymptotic system-size (N) dependence is extracted. It is shown that "thermal conductivity" depends not just on the system itself but also on the spectral...

We consider far from equilibrium heat transport in chaotic billiard chains with noninteracting charged particles in the presence of nonuniform transverse magnetic field. If half of the chain is placed in a strong magnetic field, or if the strength of the magnetic field has a large gradient along the chain, heat current is shown to be asymmetric with respect to exchange of the temperatures of th...

We present a model for a thermal Brownian motor based on Feynman’s famous ratchet and pawl device. Its main feature is that the ratchet and the pawl are in different thermal baths and connected by an harmonic spring. We simulate its dynamics, explore its main features and also derive an approximate analytical solution for the mean velocity as a function of the external torque applied and the te...