Fano resonance in a two-level quantum dot side-coupled to leads

TL;DR

This paper theoretically investigates how Coulomb interactions and interference affect Fano resonance lineshapes in a two-level quantum dot system connected to leads, revealing nonmonotonic occupation effects and deformation of the resonance profile.

Contribution

It introduces a theoretical framework linking lineshape deformation to interaction-induced nonmonotonic level occupation in a two-level quantum dot with direct lead coupling.

Findings

Deformation of Fano lineshape due to Coulomb interaction and interference.

Connection between lineshape deformation and nonmonotonic level occupation.

Dependence of lineshape on direct channel transmission and coupling matrix elements.

Abstract

We theoretically study Fano resonance in a two-level quantum dot side-coupled to two leads, which are connected by a direct channel. The resonance lineshape is found to be deformed, from the conventional Fano form, by interlevel Coulomb interaction and interlevel interference. We derive the connection between the lineshape deformation and the interaction-induced nonmonotonicity of level occupation, which may be useful for experimental study. The dependence of the lineshape on the transmission of the direct channel and on the dot-lead coupling matrix elements is discussed.