A theory is developed for the emission noise at frequency ν in a quantum dot in the presence of Coulomb interactions and asymmetric couplings to the reservoirs. We give an analytical expression for the noise in terms of the various transmission amplitudes. Including the inelastic scattering contribution, it can be seen as the analog of the Meir-Wingreen formula for the current. A physical interpretation is given on the basis of the transmission of one electron-hole pair to the concerned reservoir where it emits an energy after recombination. We then treat the interactions by solving the self-consistent equations of motion for the Green functions. The results for the noise derivative versus eV show a zero value until eV=hν, followed by a Kondo peak in the Kondo regime, in good agreement with recent measurements in carbon nanotube quantum dots.

First principles molecular dynamics is employed to investigate thermal transport in glassy GeTe4, a subsystem of several ternary phase-change materials. As a first result, we found modes localized on a few atoms in the vibrational density of states. The thermal transport is further rationalized by calculating the thermal conductivity for a range of system sizes and shapes via the approachto-equilibrium methodology. By considering the length dependence of the thermal conductivity, we provide evidence of propagative modes with mean free paths as long as 6 nm, i. e. well beyond short range order distances. Extrapolation of our bulk thermal conductivity to macroscopic sizes is in full agreement with the experimental values. Finally, we assess phenomenological models developed for the thermal conductivity of disordered materials, by enriching their intrinsic significance via the insertion in their analytical expression of values obtained via first principles molecular dynamics.

Thermal conductivity of amorphous Ge2Sb2Te5 at the nanoscale from first-principles calculations.