A quantum coherent approach to transport and noise in double barrier resonant diodes: shot noise a way to distinguish coherent from sequential tunneling

摘要

We implement a quantum approach which includes long range Coulomb interactionand investigate current voltage characteristics and shot noise in doublebarrier resonant diodes. Theory applies to the region of low applied voltagesup to the region of the current peak and considers the wide temperature rangefrom zero to room temperature. The shape of the current voltage characteristicis well reproduced and we confirm that even in the presence of Coulombinteraction shot noise can be suppressed with a Fano factor well below thevalue of 0.5. This feature is a signature of coherent tunnelling since thestandard sequential tunnelling predicts in general a Fano factor equal to orgreater than the value 0.5. This giant suppression is a consequence of Pauliprinciple as well as long range Coulomb interaction. The theory generalizesprevious findings and is compared with experiments.