Self-consistent approach for the quantum confined Stark effect in shallow quantum wells

TL;DR

This paper introduces a self-consistent complex scaling method to efficiently analyze exciton characteristics in quantum wells under electric fields, capturing resonance positions and broadening with high accuracy.

Contribution

The paper presents a novel, computationally efficient self-consistent approach for calculating exciton resonances and broadening in quantum wells subjected to external electric fields.

Findings

Real part of exciton potential is insensitive to electric field changes below ionization threshold.

Imaginary part of the potential exhibits non-analytical field dependence.

Method accurately relates exciton quasi-energy to zero-field bound states.

Abstract

A computationally efficient, self-consistent complex scaling approach to calculating characteristics of excitons in an external electric field in quantum wells is introduced. The method allows one to extract the resonance position as well as the field-induced broadening for the exciton resonance. For the case of strong confinement the trial function is represented in factorized form. The corresponding coupled self-consistent equations, which include the effective complex potentials, are obtained. The method is applied to the shallow quantum well. It is shown that in this case the real part of the effective exciton potential is insensitive to changes of external electric field up to the ionization threshold, while the imaginary part has non-analytical field dependence and small for moderate electric fields. This allows one to express the exciton quasi-energy at some field through the renormalized expression for the zero-field bound state.