Plasmon-assisted two-photon Rabi oscillations in a semiconductor quantum dot -- metal nanoparticle heterodimer

TL;DR

This paper theoretically explores two-photon Rabi oscillations in a semiconductor quantum dot-metal nanoparticle heterodimer, revealing enhanced entangled photon pair generation due to plasmonic effects and quantum dot-metal interactions.

Contribution

It introduces a novel theoretical analysis of two-photon Rabi oscillations in a quantum dot-metal nanoparticle system, highlighting the impact of plasmonic enhancement on entangled photon production.

Findings

Increased number of Rabi cycles per pulse compared to isolated quantum dots.

Growth in entangled photon pairs generated per pulse due to plasmonic effects.

Radiative decay negatively affects two-photon Rabi oscillations.

Abstract

Tho-photon Rabi oscillations hold potential for quantum computing and quantum information processing, because during a Rabi cycle a pair of entangled photons may be created. We theoretically investigate the onset of this phenomenon in a heterodimer comprising a semiconductor quantum dot strongly coupled to a metal nanoparticle. Two-photon Rabi oscillations in this system occur due to a coherent two-photon process involving the ground-to-biexciton transition in the quantum dot. The presence of a metal nanoparticle nearby the quantum dot results in a self-action of the quantum dot via the metal nanoparticle, because the polatization state of the latter depends on the quantum state of the former. The interparticle interaction gives rise to two principal effects: (i) - enhancement of the external field amplitude and (ii) - renormalization of the quantum dot's resonance frequencies and relaxation rates of the off-diagonal density matrix elements, both depending on the populations of the quantum dot's levels. Here, we focus on the first effect, which results in interesting new features, in particular, in an increased number of Rabi cycles per pulse as compared to an isolated quantum dot and subsequent growth of the number of entangled photon pairs per pulse. We also discuss the destructive role of radiative decay of the excitonic states on two-photon Rabi oscillations for both an isolated quantum dot and a heterodimer.