Electron Transport through T-Shaped Double-Dots System

TL;DR

This paper investigates how electron correlation effects influence transport in a T-shaped double-dot system, revealing a Fano-like suppression of conductance in the Kondo regime due to inter-dot interactions.

Contribution

It introduces a detailed analysis of correlation effects in T-shaped double-dot systems, highlighting the impact of the non-connected dot on conductance and discovering a novel Fano-like suppression phenomenon.

Findings

The non-connected dot significantly affects conductance behavior.

A Fano-like suppression of Kondo conductance occurs when dot levels align.

The conductance behavior differs markedly from single-dot systems.

Abstract

Correlation effects on electron transport through a system of T-shaped double-dots are investigated, for which only one of the dots is directly connected to the leads. We evaluate the local density of states and the conductance by means of the non-crossing approximation at finite temperatures as well as the slave-boson mean field approximation at zero temperature. It is found that the dot which is not directly connected to the leads considerably influences the conductance, making its behavior quite different from the case of a single-dot system. In particular, we find a novel phenomenon in the Kondo regime with a small inter-dot coupling, i.e. Fano-like suppression of the Kondo-mediated conductance, when two dot levels coincide with each other energetically.