Defects in quantum ring to control high-harmonic spectrum

Abstract

The high-harmonic generation from a structured quantum ring (SQR) driven by an intense laser field is presented within the single active electron approximation. The spectrum is studied by varying the symmetry of the physical system. The standard SQR (six identical and equidistant dots in a ring) presents a 60° rotational symmetry, that in this work is broken, moving or changing only one potential hole. We find that careful designed breaking of the geometrical symmetry of the SQR opens the possibility of controlling the characteristics of the harmonic lines such as intensity and polarization. HHG analysis of the emission spectrum performed through a Morlet wavelet, shows that the high-frequency emission occurs during short time intervals

Laser Assisted Dirac Electron in a Magnetized Annulus

“…As mentioned in the Introduction, a plethora of schemes, requiring the presence of a magnetic field, has been advanced to overpass the problem. Rings and annuli are perfectly suitable to be used with a magnetic field because of their circular symmetry; they provide a fundamental environment for basic and applicative use [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]. Now, we discuss the problem of the annulus crossed by an orthogonal static magnetic field B 0 .…”

On the dynamics of confined particles: a laser test

“…Moreover rings appear to provide the base for designing and implementing fast operating logic circuits [22][23][24]. Today the possibility of controlling the yield and the polarization of the electro magnetic radiation is required; several schemes have been proposed to achieve this goal by using the possibilities offered by high order harmonic generation in atoms and molecules [25,26]; rings can be designed almost at will and may open a road toward the control of the polarization of the emission [27].…”