Pathway to scalable photonic quantum computing beyond linear optics

Photons hold great promise as a platform for quantum computing: they are fast, experience few noise processes, can be natively networked using optical fibre, and require minimal cryogenics. However, standard approaches using linear optics are fundamentally limited by probabilistic photon generation and entangling gates, leading to substantial hardware overheads.

 

I will describe a novel architecture for fault-tolerant quantum computing that incorporates strong single-photon nonlinearities into a photonic GHZ-measurement-based approach. These interactions substantially reduce resource overheads compared to linear-optical approaches and yield a significantly higher baseline loss tolerance, reaching ∼12% using a 32-photon resource state and a foliated surface code.

 

I will then give an overview of our progress towards realising optical nonlinearities through cavity-enhanced light-matter interactions and our development of an underpinning integrated photonics platform capable of fast, low-loss optical switching.

 

Finally, I will place these advances in the context of our roadmap for delivering practical photonic quantum computing, including the deployment of our near-term PT-Series photonic processors targeting quantum advantage in hybrid quantum-classical applications.