Wave-Shape-Tolerant Photonic Quantum Gates

TL;DR

This paper introduces wave-shape-tolerant photonic quantum gates that maintain photon wavepacket properties during processing, enabling scalable quantum computation with a broader range of photon states, including correlated and entangled ones.

Contribution

It demonstrates a novel method using coherent photon conversion to create quantum gates that are insensitive to photon wavepacket shapes and correlations, preserving these features during computation.

Findings

Gates are insensitive to photon wavepacket shapes and correlations.

The method preserves wavepacket properties during processing.

Entangled photon wavepackets are processed more effectively.

Abstract

Photons, acting as ``flying qubits'' in propagation geometries such as waveguides, appear unavoidably in the form of wavepackets (pulses). The actual shape of the photonic wavepacket, as well as possible temporal/spectral correlations between the photons, play a critical role in successful scalable computation. Currently, unentangled indistinguishable photons are considered as a suitable resource for scalable photonic circuits. Here we show that using so called coherent photon conversion, it is possible to construct flying-qubit gates, which are not only insensitive to waveshapes of the photons and temporal/spectral correlations between them, but which also fully preserve these waveshapes and correlations upon the processing. This allows using photons with correlations and purity in a very broad range for a scalable computation. Moreover, such gates can process entangled photonic wavepackets even more effectively than unentangled ones.