Electron trapping via magnetic and laser fields in gapped graphene quantum dots

TL;DR

This paper investigates how magnetic fields, energy gaps, and circularly polarized laser light influence electron trapping and scattering in graphene quantum dots, revealing ways to control electron confinement and transport.

Contribution

It introduces a combined theoretical approach using Floquet theory and the Dirac equation to analyze electron scattering in GQDs under multiple external influences, highlighting new control mechanisms.

Findings

Energy gap and laser light enhance electron localization.

Laser polarization affects scattering and confinement.

Quasi-bound state lifetime increases with external fields.

Abstract

We study electron scattering in graphene quantum dots (GQDs) under the combined influence of a magnetic field, an energy gap, and circularly polarized laser irradiation. Using the Floquet approach and the Dirac equation, we derive the energy spectrum solutions. The scattering coefficients are calculated explicitly by matching the eigenspinors at the GQD interfaces, revealing a dependence on several physical parameters. In addition, we compute the scattering efficiency, the electron density distribution, and the lifetime of the quasi-bound states. Our numerical results show that the presence of an energy gap and circularly polarized laser irradiation enhances the localization of the electron density within the GQDs, leading to an increase in the lifetime of the quasi-bound states. In particular, the intensity and polarization of the light influence the scattering process, allowing the manipulation of the electron confinement state. These results highlight the importance of combining magnetic fields and polarized light to control electronic transport in graphene nanostructures.