Fast generation of entangled photon pairs from a single quantum dot embedded in a photonic crystal cavity

TL;DR

This paper proposes a rapid method for generating entangled photon pairs from a single quantum dot embedded in a photonic crystal cavity, achieving high entanglement concurrence and enabling entanglement distillation.

Contribution

It introduces a novel scheme for fast entangled photon generation using quantum dots in photonic crystal cavities, with experimentally feasible parameters and entanglement enhancement techniques.

Findings

Photon concurrence exceeds 0.7 and 0.8 in different generation schemes.

Entanglement can be distilled using spectral filtering.

The method is compatible with current experimental setups.

Abstract

We present a scheme for the fast generation of entangled photons from a single quantum dot coupled to a planar photonic crystal that support two orthogonally polarized cavity modes. We discuss ``within generation'' and ``across generation'' of entangled photons when both biexciton to exciton, and exciton to ground state transitions, are coupled through cavity modes. In the across generation, the photon entanglement is restored through a time delay between the photons. The two photon concurrence, which is a measure of entanglement, is greater than 0.7 and 0.8 using experimentally achievable parameters in across generation and within generation, respectively. We also show that the entanglement can be distilled in both cases using a simple spectral filter.