Transport properties of strongly correlated electrons in quantum dots using a simple circuit model

TL;DR

This paper introduces a simple circuit model to explain the splitting of the zero-bias peak in quantum dot experiments, attributing it to Fano anti-resonance caused by side-connected quantum dots, providing an alternative to RKKY explanations.

Contribution

The paper presents a simple circuit model that qualitatively reproduces experimental results on nonlocal spin control and zero-bias-peak splitting in quantum dots, offering an alternative explanation to RKKY interactions.

Findings

The circuit model reproduces experimental zero-bias-peak splitting.

Fano anti-resonance explains the splitting in quantum dots.

The model offers an alternative to RKKY-based explanations.

Abstract

Numerical calculations are shown to reproduce the main results of recent experiments involving nonlocal spin control in nanostructures (N. J. Craig et al., Science 304, 565 (2004)). In particular, the splitting of the zero-bias-peak discovered experimentally is clearly observed in our studies. To understand these results, a simple "circuit model" is introduced and shown to provide a good qualitative description of the experiments. The main idea is that the splitting originates in a Fano anti-resonance, which is caused by having one quantum dot side-connected in relation to the current's path. This scenario provides an explanation of Craig et al.'s results that is alternative to the RKKY proposal, which is here also addressed.