An entangling quantum-logic gate operated with an ultrabright single photon-source

TL;DR

This paper demonstrates an entangling quantum-logic gate using an ultrabright solid-state single-photon source, achieving high fidelity and entanglement thresholds with improved source brightness.

Contribution

It introduces a photonic quantum-logic gate operated with a highly bright solid-state single-photon source, showing significant entanglement and fidelity improvements over previous methods.

Findings

Achieved a truth table overlap of 68.4% at 0.56 photons/pulse brightness.

Bell-state fidelity exceeded 50% threshold, reaching 71.0% at 0.15 photons/pulse.

Demonstrated entangling operation with high source brightness and fidelity.

Abstract

We demonstrate unambiguous entangling operation of a photonic quantum-logic gate driven by an ultrabright solid-state single-photon source. Indistinguishable single photons emitted by a single semiconductor quantum dot in a micropillar optical cavity are used as target and control qubits. For a source brightness of 0.56 collected photons-per-pulse, the measured truth table has an overlap with the ideal case of 68.4%, increasing to 73.0% for a source brightness of 0.17 photons- per-pulse. The gate is entangling: at a source brightness of 0.48, the Bell-state fidelity is above the entangling threshold of 50%, and reaches 71.0% for a source brightness of 0.15.