Bessel-beam-assisted persistent current in toroidal semiconductor quantum dots

Abstract

Quantum dots offer a flexible platform for studying quantum coherence and transport phenomena at the nanoscale. The closed-loop shape of toroidal quantum dots, in particular, enables quantum interference of electron wave functions, hence facilitating the study of persistent currents. Persistent currents are sensitive to confinement geometry, magnetic flux quantization, and external perturbations, making them valuable probes of mesoscopic physics. The general problem addressed here is how magnetic and intense laser fields jointly influence the magnitude and profile of persistent currents in toroidal quantum dots. Here, we show that the persistent current is strongly modified by the presence and configuration of laser fields, with Gaussian and Bessel profiles producing distinct resonant features, while shifting the Bessel field results in a nearly linear current response. Machine learning techniques were employed in the calculations to optimize efficiency and minimize computational costs. The results reveal that the profile and spatial positioning of optical fields can be used to tailor current behavior. It is shown how optical variations affect current profiles through confinement modification and symmetry breaking, providing new insights into the control of quantum transport. In a broader context, the study emphasizes how geometry, magnetic flux, and optical fields interact in nanoscale structures, offering new opportunities for the accurate engineering of quantum states and currents. Quantum devices that depend on coherence, topological states, or laser-induced transport in nanostructures may be affected by this kind of control. • Laser-Assisted Persistent Currents in Toroidal Quantum Dots are Discussed • Gaussian and Bessel Laser Beams Induce Distinct Current Responses • Centered Laser Beams Enhance Current Oscillations • Shifted Bessel Beams Initiate Nearly Linear Current Response.