Dicke effect in a quantum wire with side-coupled quantum dots

TL;DR

This paper theoretically investigates the Dicke effect in a quantum wire with side-coupled quantum dots, revealing how asymmetry influences energy bands and transmission properties, with potential control over band edges.

Contribution

It provides analytical expressions for transmission and phase, and demonstrates the control of energy bands via asymmetry, highlighting an analogy with the optical Dicke effect.

Findings

Allowed band formation depends on up-down asymmetry.

Band edges can be tuned by asymmetry degree.

Transmission spectrum exhibits forbidden and allowed bands.

Abstract

A system of an array of side-coupled quantum-dots attached to a quantum wire is studied theoretically. Transport through the quantum wire is investigated by means of a noninteracting Anderson tunneling Hamiltonian. Analytical expressions of the transmission probability and phase are given. The transmission probability shows an energy spectrum with forbidden and allowed bands that depends on the up-down asymmetry of the system. In up-down symmetry only the gap survives, and in up-down asymmetry an allowed band is formed. We show that the allowed band arises by the indirect coupling between the up and down quantum dots. In addition, the band edges can be controlled by the degree of asymmetry of the quantum dots. We discuss the analogy between this phenomenon with the Dicke effect in optics.