Localized all-optical control of single semiconductor quantum dots through plasmon-polariton-induced screening

TL;DR

This paper demonstrates a method for dynamically tuning the energy states of a single semiconductor quantum dot by optically modifying its local dielectric environment with a plasmonic structure, preserving its intrinsic properties for real-time control.

Contribution

It introduces a novel approach to actively control quantum dot properties using plasmonic structures without altering their intrinsic optical characteristics.

Findings

Achieved real-time tuning of quantum dot energy states.

Preserved intrinsic optical properties during modulation.

Enabled potential for ultrafast switching and modulation.

Abstract

Due to their ability to strongly modify the local electromagnetic (EM) field through the excitation of surface plasmon polaritons (SPPs), plasmonic nanostructures have been often used to reshape the emission direction and enhance the radiative decay rate of quantum emitters, such as semiconductor quantum dots (QDs). These features are essential for quantum information processing, nanoscale photonic circuitry and optoelectronics. However, the modification and enhancement demonstrated thus far often drastically alter the local energy density of the emitters, and hence their intrinsic properties, leaving little room for active control. Here, we demonstrate dynamic tuning of the energy states of a single semiconductor QD by optically modifying its local dielectric environment with a nearby plasmonic structure, instead of directly coupling it to the QD. This method leaves the original intrinsic optical properties of the QD intact, enabling the opportunity of tuning its optical properties in real time. This capability is highly desired in applications requiring ultrafast switching and modulation mechanisms.