Characterization of shell filling of interacting polarons in a quantum dot through their optical absorption

TL;DR

This paper develops a method to analyze the ground-state energy and optical absorption spectra of interacting polarons in quantum dots, revealing features related to spin transitions and electron-phonon interactions.

Contribution

It introduces a path-integral approach combined with a variational principle to study finite polaron systems in quantum dots, accounting for fermion statistics and arbitrary coupling.

Findings

Ground-state energy depends on number of polarons and coupling strength.

Optical spectra show features linked to spin state transitions.

Method enables detailed analysis of polaron interactions in confined systems.

Abstract

The method for calculating the ground-state energy and the optical conductivity spectra is developed for a system of a finite number of interacting arbitrary-coupling polarons in a spherical quantum dot with a parabolic confinement potential. The path-integral formalism for identical particles is used in order to take into account the fermion statistics. Using a generalization of the Jensen-Feynman variational principle, the ground-state energy of a confined N-polaron system is analyzed as a function of N and of the electron-phonon coupling strength. The calculated optical conductivity spectra of the N-polaron system in a quantum dot manifest features related to ground-state transitions between states with different total spin.