A photonic cluster state machine gun

TL;DR

This paper introduces a method to transform specific single photon sources into devices that can reliably produce long streams of photonic cluster states on demand, enhancing the feasibility of linear optical quantum computing.

Contribution

The authors propose a novel approach to convert quantum dot sources into a photonic cluster state machine gun, improving photon emission rates and fault tolerance in quantum computing.

Findings

High entangled-photon emission rates are achievable with current quantum dot technology.

Pauli-error rates per photon are less than 0.2%, suitable for fault-tolerant quantum computing.

The method mitigates issues of photon indistinguishability and exciton dephasing in quantum dots.

Abstract

We present a method to convert certain single photon sources into devices capable of emitting large strings of photonic cluster state in a controlled and pulsed "on demand" manner. Such sources would greatly reduce the resources required to achieve linear optical quantum computation. Standard spin errors, such as dephasing, are shown to affect only 1 or 2 of the emitted photons at a time. This allows for the use of standard fault tolerance techniques, and shows that the photonic machine gun can be fired for arbitrarily long times. Using realistic parameters for current quantum dot sources, we conclude high entangled-photon emission rates are achievable, with Pauli-error rates per photon of less than 0.2%. For quantum dot sources the method has the added advantage of alleviating the problematic issues of obtaining identical photons from independent, non-identical quantum dots, and of exciton dephasing.