Deterministic generation of concatenated graph codes from quantum emitters

TL;DR

This paper proposes practical schemes for generating concatenated graph codes using quantum emitters, enabling fault-tolerant photonic quantum computation resilient to photon loss without auxiliary photons.

Contribution

It introduces deterministic methods for creating concatenated graph codes from quantum emitters, facilitating fault-tolerant quantum computing in photonic systems.

Findings

Schemes enable fault-tolerant fusion-based quantum computation

High photon loss tolerance demonstrated in practical regimes

No auxiliary photons needed for the proposed schemes

Abstract

Photon loss is the dominant noise mechanism in photonic quantum technologies. Designing fault-tolerant schemes with high tolerance to loss is thus a central challenge in scaling photonic quantum information processors. Concatenation of a fault-tolerant construction with a code able to efficiently correct loss is a promising approach to achieve this, but practical ways to implement code concatenation with photons have been lacking. We propose schemes for generating concatenated graph codes using multi-photon emission from two quantum emitters or a single quantum emitter coupled to a memory; capabilities available in several photonic platforms. We show that these schemes enable fault-tolerant fusion-based quantum computation in practical regimes with high photon loss and standard fusion gates without the need for auxiliary photons.