Double-dot transport in the spin blockade regime

Gloria Platero^1,* and Jesús Iñarrea^1,2

We analyzed theoretically electronic transport through a double quantum dot in the spin blockade regime in the presence of hyperfine interaction. The electron and nuclei spin interaction produces electron spin flip which partially removes spin blockade. Induced nuclei spin polarization produces a finite magnetic field which acts on the electrons generating an additional Zeeman splitting of the electronic spin up and down levels in each quantum dot. This additional Zeeman splitting changes dynamically with the electronic levels occupation. Then, strong feed-back between the induced nuclear polarization within each quantum dot and the electronic charge distribution occurs and it produces strong non linearities in the current and in the nuclear polarization of each quantum dot as a function of magnetic field, such as hysteretic behavior. This bistable behavior is analyzed for different densities of nuclei within each quantum dot, i.e., for different intensities of the hyperfine interaction.

PACS: 73.63.Kv, 73.23.Hk, 72.10.Di