Electronic transport of a T-shaped double-quantum-dot system in the Coulomb blockade regime

We studied the electronic transport properties of a T-shaped double-quantum-dot system in the Coulomb blockade regime when the onsite Coulomb interaction parameters U1 and U2 have finite values in both component dots. Our analysis is done in the so-called beyond Hartree-Fock approximation that includes contributions related to both normal and mixed averages of various number-like operators in the system. We provide an analytic formula for the main’s dot Green function in the case of large onsite Coulomb interaction parameters (U1 = U2 → ∞), and find that with a good approximation, this limit is realized when the ratio U1/t = U2/t ≥ 30, t being the interdot electron tunneling between the two component dots of the structures. In the most general situation of the Coulomb blockade regime (U1 ≠ U2) the system conductivity presents two dips corresponding to the Fano-Kondo effect and the system’s shot noise and electronic current present a series of plateaus that should be visible in experimental setups.