Development of polaron-transformed explicitly correlated full configuration interaction method for investigation of quantum-confined Stark effect in GaAs quantum dots

TL;DR

This paper introduces a novel polaron-transformed explicitly correlated full configuration interaction method to study the impact of external electric fields on electron-hole interactions in GaAs quantum dots, providing detailed insights into exciton behavior.

Contribution

The paper develops a new computational approach combining polaron transformation and explicitly correlated CI to accurately model electric field effects in quantum dots.

Findings

Electric field significantly reduces exciton binding energy and recombination probability.

Recombination probability is more sensitive to electric field than binding energy.

Exciton binding energy approaches zero at high electric fields.

Abstract

The effect of external electric field on electron-hole correlation in GaAs quantum dots is investigated. The electron-hole Schrodinger equation in the presence of external electric field is solved using explicitly correlated full configuration interaction (XCFCI) method and accurate exciton binding energy and electron-hole recombination probability are obtained. The effect of the electric field was included in the 1-particle single component basis functions by performing variational polaron transformation. The quality of the wavefunction at small inter-particle distances was improved by using Gaussian-type geminal function that depended explicitly on the electron-hole separation distance. The parameters of the explicitly correlated function were determined variationally at each field strength. The scaling of total exciton energy, exciton binding energy, and electron-hole recombination probability with respect to the strength of the electric field was investigated. It was found that a 500 kV/cm change in electric field reduces the binding energy and recombination probability by a factor of 2.6 and 166, respectively. The results show that the eh-recombination probability is affected much more strongly by the electric field than the exciton binding energy. Analysis using the polaron-transformed basis indicates that the exciton binding should asymptotically vanish in the limit of large field strength.