Deterministic photon storage and readout in a semimagnetic quantum-dot--cavity system doped with a single Mn ion

TL;DR

This paper proposes a theoretical method for single-photon storage and retrieval in a quantum-dot--cavity system doped with a Mn ion, enabling photon delay of nearly 100 times longer than exciton lifetime.

Contribution

It introduces a novel scheme for photon storage using bright to dark exciton conversion mediated by a magnetic ion in a quantum dot-cavity system.

Findings

Photon can be stored for nearly 100 times longer than exciton lifetime.

The scheme enables on-demand readout of the stored photon.

The method relies on Stark shift-induced resonance for exciton transfer.

Abstract

Light trapping is a crucial mechanism for synchronization in optical communication. Especially on the level of single photons, control of the exact emission time is desirable. In this paper, we theoretically propose a single-photon buffering device composed of a quantum dot doped with a single Mn atom in a cavity. We present a method to detain a single cavity photon as an excitation of the dot. The storage scheme is based on bright to dark exciton conversion performed with an off-resonant external optical field and mediated via a spin-flip with the magnetic ion. The induced Stark shift brings both exciton states to resonance and results in an excitation transfer to the optically inactive one. The stored photon can be read out on demand in the same manner by repopulating the bright state, which has a short lifetime. Our results indicate the possibility to suspend a photon for almost two orders of magnitude longer than the lifetime of the bright exciton.