Eur. Phys. J. B (2013) 86: 102
https://doi.org/10.1140/epjb/e2013-30567-8

Regular Article

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

¹ Department of Physics, California State University, Fullerton, CA 92834, USA
² Department of Theoretical Physics, “Babeş-Bolyai” University, 40084 Cluj-Napoca, Romania
³ Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany

^a e-mail: itifrea@fullerton.edu

Received: 10 July 2012
Received in final form: 5 October 2012
Published online: 18 March 2013

Abstract

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.