Detection of local-moment formation using the resonant interaction between coupled quantum wires

TL;DR

This paper investigates how many-body interactions in coupled quantum wires influence transport properties, demonstrating that local magnetic moments can be detected via conductance measurements in a novel device structure.

Contribution

It introduces a theoretical framework showing that coupled quantum wires can be used to detect local magnetic moments through conductance peaks.

Findings

Detection of a conductance peak indicating local magnetic moment formation

Theoretical explanation matching recent experimental observations

Coupled quantum wires as a system for magnetic-moment detection

Abstract

We study the influence of many-body interactions on the transport characteristics of a novel device structure, consisting of a pair of quantum wires that are coupled to each other by means of a quantum dot. Under conditions where a local magnetic moment is formed in one of the wires, we show that tunnel coupling to the other gives rise to an associated peak in its density of states, which can be detected directly in a conductance measurement. Our theory is therefore able to account for the key observations in the recent study of T. Morimoto et al. [Appl. Phys. Lett. {\bf 82}, 3952 (2003)], and demonstrates that coupled quantum wires may be used as a system for the detection of local magnetic-moment formation.