Ground state and optical conductivity of interacting polarons in a quantum dot
Abstract
The ground-state energy, the addition energies and the optical absorption spectra are derived for interacting polarons in parabolic quantum dots in three and two dimensions. A path integral formalism for identical particles is used in order to take into account the fermion statistics. The approach is applied to both closed-shell and open-shell systems of interacting polarons. 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 constant. As distinct from the few-electron systems without the electron-phonon interaction, three types of spin polarization are possible for the ground state of the few-polaron systems: (i) a spin-polarized state, (ii) a state where the spin is determined by Hund's rule, (iii) a state with the minimal possible spin. A transition from a state fulfilling Hund's rule, to a spin-polarized state occurs when decreasing the electron density. In the strong-coupling limit, the system of interacting polarons turns into a state with the minimal possible spin. These transitions should be experimentally observable in the optical absorption spectra of quantum dots.
Cite
@article{arxiv.cond-mat/0405529,
title = {Ground state and optical conductivity of interacting polarons in a quantum dot},
author = {S. N. Klimin and V. M. Fomin and F. Brosens and J. T. Devreese},
journal= {arXiv preprint arXiv:cond-mat/0405529},
year = {2009}
}
Comments
33 pages, 9 figures, E-mail addresses: [email protected], [email protected], [email protected], [email protected], accepted for Phys. Rev. B