Fermi-liquid versus non-Fermi-liquid behavior in triple quantum dots

TL;DR

This paper investigates how electron hopping influences the transition between Fermi-liquid and non-Fermi-liquid behaviors in triple quantum dots, revealing conditions for the two-channel Kondo effect and associated conductance signatures.

Contribution

It identifies the parameter range where the three-impurity Anderson model exhibits non-Fermi-liquid behavior and describes the conductance evolution across different temperature regimes.

Findings

Non-Fermi-liquid behavior occurs over a wide temperature range.

Conductance through side dots reaches half of the quantum unit in NFL regime.

System transitions to Fermi-liquid ground state with unitary conductance at low temperatures.

Abstract

We study the effect of electron hopping in triple quantum dots modelled by the three-impurity Anderson model. We determine the range of hopping parameters where the system exhibits the two-channel Kondo effect and has non-Fermi-liquid properties in a wide temperature interval. As this interval is entered from above, the conductance through the side dots increases to a half of the conductance quantum, while the conductance through the system remains small. At lower temperatures the conductance through the system increases to the unitary limit as the system crosses over to the Fermi-liquid ground state. Measuring the differential conductance in a three terminal configuration provides an experimental probe into the NFL behavior.