Rapid creation of distant entanglement by multiphoton resonant fluorescence

TL;DR

This paper proposes a robust, high-fidelity method for entangling quantum dot spin qubits using multiphoton Gaussian states, leveraging interference effects to improve entanglement rates over single-photon schemes.

Contribution

It introduces a novel multiphoton fluorescence-based entanglement scheme that is resilient to noise and absorption, enhancing entanglement generation efficiency.

Findings

Significant increase in entanglement rate compared to single-photon methods

Robustness against photon loss and noise demonstrated

Feasible with current experimental technology

Abstract

We study a simple, effective and robust method for entangling two separate stationary quantum dot spin qubits with high fidelity using multiphoton Gaussian state. The fluorescence signals from the two dots interfere at a beam splitter. The bosonic nature of photons leads, in analogy with the Hong-Ou-Mandel effect, to selective pairing of photon holes (photon absences in the fluorescent signals). As a result, two odd photon number detections at the outgoing beams herald trion entanglement creation, and subsequent reduction of the trions to the spin ground states leads to spin-spin entanglement. The robustness of the Gaussian states is evidenced by the ability to compensate for photon absorption and noise by a moderate increase in the number of photons at the input. We calculate the entanglement generation rate in the ideal, nonideal and near-ideal detector regimes and find substantial improvement over single-photon schemes in all three regimes. Fast and efficient spin-spin entanglement creation can form the basis for a scalable quantum dot quantum computing network. Our predictions can be tested using current experimental capabilities.