Correlation effects on electron tunneling through doubly occupied quantum dots: A study beyond phenomenological models

Abstract

Electron transport through doubly occupied quantum dots is studied theoretically. Beyond the semi-classic framework of phenomenological models, a quantum mechanical solution for the cotunneling and sequential tunneling of electrons through a one-dimensional multi-level quantum dot is obtained. Correlation effects are shown to play an important role in inelastic sequential tunneling through the doubly occupied system, which accommodates four single-particle levels. It is revealed that the cotunneling conductance exhibits strong dependence on the spin configuration of the electrons confined inside the dot. Especially for the triplet configuration, the conductance shows an obvious deviation from the well-known quadratic dependence on the applied bias voltage.