Shape-independent scaling of excitonic confinement in realistic quantum wires

TL;DR

This paper presents a theoretical study showing that exciton binding energy scaling in quantum wires is governed by a universal parameter, independent of wire shape or composition, in the strong confinement regime.

Contribution

It introduces a shape- and composition-independent parameter that universally governs excitonic confinement scaling in realistic quantum wires.

Findings

Universal scaling parameter identified

Strong confinement limit shows shape independence

Shape effects are less significant than previously thought

Abstract

The scaling of exciton binding energy in semiconductor quantum wires is investigated theoretically through a non-variational, fully three-dimensional approach for a wide set of realistic state-of-the-art structures. We find that in the strong confinement limit the same potential-to-kinetic energy ratio holds for quite different wire cross-sections and compositions. As a consequence, a universal (shape- and composition-independent) parameter can be identified that governs the scaling of the binding energy with size. Previous indications that the shape of the wire cross-section may have important effects on exciton binding are discussed in the light of the present results.