Semiconductor quantum tubes: dielectric modulation and excitonic response

TL;DR

This paper theoretically investigates how dielectric modulation affects the optical properties and excitonic behavior of semiconductor quantum tubes, revealing tunable exciton binding energies through structural and dielectric design.

Contribution

It introduces a theoretical framework using Green's functions and exact diagonalization to analyze dielectric effects on excitons in quantum tubes, highlighting tunability.

Findings

Exciton binding energy varies with tube diameter in dielectric-modulated tubes.

Dielectric environment significantly influences excitonic oscillator strength.

Structural design enables control over optical properties of quantum tubes.

Abstract

We study theoretically the optical properties of quantum tubes, one-dimensional semiconductor nanostructures where electrons and holes are confined to a cylindrical shell. In these structures, which bridge between 2D and 1D systems, the electron-hole interaction may be modulated by a dielectric substance outside the quantum tube and possibly inside its core. We use the exact Green's function for the appropriate dielectric configuration and exact diagonalization of the electron-hole interaction within an effective mass description to predict the evolution of the exciton binding energy and oscillator strength. Contrary to the homogeneous case, in dielectrically modulated tubes the exciton binding is a function of the tube diameter and can be tuned to a large extent by structure design and proper choice of the dielectric media.