Correlations and spin in electric transport through quantum dots

An overview of the theory of charge and spin transport through a one-dimen- sional quantum dot attached to semi-infinite leads by tunnel barriers is given. Electron correlations and extra spin relaxation are taken into account. The tunnel rates are calculated microscopically by using the Luttinger liquid model with spin for both, the quantum dot and the leads. In the linear regime, the spin-induced parity effect is recovered. In the non-linear regime, in addition to states with fixed number of electrons in the dot, larger-spin states can be stabilized in the presence of non-Fermi liquid correlations by adjusting the tunnel barriers to be asymmetric. These states are accompanied by negative differential conductances. The latter can be destroyed by introducing extra spin-flip relaxation processes. The participation of the larger-spin states in the transport is accompanied by distinct spin fluctuations.