Laser-Controlled Polarization Effects in High-Harmonic Generation from Zero-Dimensional Nanostructures

Abstract

We investigated laser-controlled polarization effects in high-harmonic generation from graphene quantum dots driven by intense arbitrary polarized laser fields, using a tight-binding framework. The polarization state of the emitted harmonics, including ellipticity and ellipse orientation, is characterized through the Stokes parameters. We revealed that elliptically polarized driving fields can generate harmonics with linear and elliptical polarizations, and conversely that harmonics with controlled ellipticity can emerge from linearly polarized excitation. Our numerical results demonstrated that the harmonic polarization can be effectively controlled by changing the polarization of the exciting laser field, without the need for additional control elements.