Temperature dependent transport in artificial Kondo impurities and molecular junctions

The role of temperature and thermal gradients in the electronic transport through quantum conductors is lately attracting much attention. In this talk, we will discuss two different but closely related works. First, we will consider a quantum dot acting as an artificial Kondo impurity. The Kondo effect is a phenomenon which emerges from the interactions between the spin density of delocalized carriers in electron reservoirs with the spin of a localized electron in the quantum dot. A many-body singlet state is thus created, which causes a zero bias anomaly in the electrical conductance of the system. Our study shows that sufficiently strong thermal biases kill the Kondo state. Second, we will consider a molecule sandwiched between metallic electrodes. A previous work measured temperature dependent transport in a molecular transistor and employed a noninteracting model to analyze the results. Here, we will emphasize the importance of Coulomb blockade effects and will demonstrate that a magnetic field can be used to distinguish between the two models.