The effects of the intense laser and homogeneous electric fields on the electronic and intraband optical properties of a GaAs/Ga0.7 Al0.3As quantum ring

A Radu,D Laroze,A A Kirakosyan,M G Barseghyan

doi:10.1088/0268-1242/30/4/045006

Abstract

The simultaneous influences of an intense laser field and static electric field on one-electron states and intraband optical absorption coefficient are investigated in two-dimensional GaAs/GaAl0.3 As quantum ring. An analytical expression of the effective confining potential in the presence of the external fields is obtained. The one-electron energy levels and wave functions are calculated using the effective mass approximation and an exact diagonalization technique. We show that changes in the incident light polarization lead to blue- or redshifts in the intraband optical absorption spectrum. Moreover, we found that blueshift and redshift are induced by the simultaneous influences of an intense laser and lateral electric fields. The obtained theoretical results indicate a novel opportunity to tune the performance of quantum rings and to control their specific properties by means of intense laser and homogeneous electric fields.

Highlights

Quantum mechanical experiments in ring-like geometries have long fascinated the physics community, as electrons confined in nanometric rings manifest a topological quantum mechanical coherence, the Aharonov–Bohm effect [1]
We have studied the simultaneous influences of the intense laser fields (ILFs) and lateral electric field on one-electron states in GaAs/Ga0.7Al0.3 As single QRs
We have investigated the influence of the light polarization direction on the intraband absorption coefficient

Summary

Introduction

Quantum mechanical experiments in ring-like geometries have long fascinated the physics community, as electrons confined in nanometric rings manifest a topological quantum mechanical coherence, the Aharonov–Bohm effect [1]. In the past decade a large number of theoretical investigations were devoted to the study of electronic and impurity states and intraband optical properties in nanostructures under the simultaneous influence of ILF and external electric field. Using the effective mass and parabolic band approximations and a variational procedure Duque et al calculated the combined effects of intense laser radiation, hydrostatic pressure, and applied electric field on a shallowdonor impurity states confined in cylindrical-shaped single and double GaAs/Ga1−xAlxAs QD [28]. Having this motivation, the present work aims at the theoretical investigation of the combined influences of the ILF and lateral electric field (electric field direction is contained in the plane of the structure) on one-electron states and intraband optical absorption coefficient of GaAs/Ga0.7Al0.3As two-dimensional QR.

Theoretical framework

Results and discussion

Conclusions