Sequential generation of linear cluster states from a single photon emitter

TL;DR

This paper presents a resource-efficient method to generate linear cluster states of photons using a single entangling gate and a quantum dot source, enabling scalable photonic quantum computing.

Contribution

It introduces a fiber loop setup with a single entangling gate to produce scalable linear cluster states from a quantum dot source.

Findings

Generated linear cluster states up to four photons

Achieved high efficiency with a single entangling gate

Potential for scalable quantum computing applications

Abstract

Light states composed of multiple entangled photons - such as cluster states - are essential for developing and scaling-up quantum computing networks. Photonic cluster states with discrete variables can be obtained from single-photon sources and entangling gates, but so far this has only been done with probabilistic sources constrained to intrinsically-low efficiencies, and an increasing hardware overhead. Here, we report the resource-efficient generation of polarization-encoded, individually-addressable, photons in linear cluster states occupying a single spatial mode. We employ a single entangling-gate in a fiber loop configuration to sequentially entangle an ever-growing stream of photons originating from the currently most efficient single-photon source technology - a semiconductor quantum dot. With this apparatus, we demonstrate the generation of linear cluster states up to four photons in a single-mode fiber. The reported architecture can be programmed to generate linear-cluster states of any number of photons with record scaling ratios, potentially enabling practical implementation of photonic quantum computing schemes.