Structured beam controlled super-resolution in quantum dots via rapid adiabatic passage

TL;DR

This paper proposes a theoretical super-resolution microscopy technique using rapid adiabatic passage in quantum dots with structured beams, demonstrating improved imaging resolution and robustness against phonon effects.

Contribution

It introduces a novel RAP-based super-resolution scheme employing structured beams and Bessel modulation to suppress rings and enhance image resolution in quantum dots.

Findings

Super-resolved images are achievable with structured beams and appropriate pulse areas.

Low pulse areas are affected by exciton-phonon coupling, distorting images.

High pulse areas mitigate phonon effects, preserving resolution.

Abstract

We theoretically investigate rapid adiabatic passage (RAP) based super-resolution microscopy in a two-level quantum dot (QD) system. The system consists of a QD interacting with two structured beams, accompanied by chirping and a time delay. The central concept of this work is inspired by the stimulated emission depletion (STED) microscopy technique. To understand the physical mechanism behind super-resolved spot formation, we employ a variational master equation for the density matrix, incorporating both radiative and non-radiative decay processes. A suitably chosen spatiotemporal envelope of the structured beams enables the formation of a super-resolved image. Unwanted low-intensity circular rings around the focal spot are suppressed using Bessel-modulated truncated structured Laguerre-Gaussian (LG) and super-Gaussian (SG) beams. We also study the temperature dependence of the imaging scheme. The numerical results confirm that at low pulse areas, exciton-phonon coupling distorts the image, whereas at higher pulse areas, exciton-phonon decoupling preserves the image resolution. Hence, the proposed scheme may open up new possibilities for nanoscale imaging and bioimaging applications using QDs.