The rules of quantum mechanics promise information processing technologies that are inherently more powerful than their classical counterparts: examples include quantum computing, unconditionally secure communication, and quantum-enhanced precision sensing. After several decades of intensive theoretical and experimental efforts, the field of quantum information processing is on the cusp of a critical moment: over the next decade, quantum computers and special-purpose quantum information processors will be capable of solving problems that classical computers cannot. The possibility of powerful new quantum information processors has ignited major investment around the globe by governments (viz. the EC’s €1B Quantum Technologies Flagship, China’s Quantum Satellite) and industry (Google, Microsoft, DWave, IBM). Photons play a central role in quantum computing and quantum networks due to their low noise properties, excellent modal control and long distance propagation. Photonic integrated circuit technology has enabled orders of magnitude improvements in component density, propagation loss, and phase stability. These advances have made possible proof-of-principle demonstrations of central quantum protocols, such as (compiled) factorization and quantum simulation of energy levels of small molecules.
Advancing the field to computationally hard problems requires a new generation of ‘quantum photonic processor’ that efficiently integrates nonclassical light generation, high-fidelity mode transformations and nonlinear photon-photon interactions. As quantum photonic technology advances new applications areas must be discovered where near-term quantum processors will likely have impact. This symbiotic development of hardware and algorithms is a central tenet of this program. ‘Very-Large-Scale Quantum Photonic Processors’ develops the next generation of quantum optical technology using the platform of silicon photonics. Silicon photonics leverages large-scale silicon manufacturing and CMOS technology to develop micron-scale photonic structures at an unprecedented component density and scale.
Applying silicon photonic technology to the quantum regime, and at a scale where classical computers can no longer keep pace, requires breakthroughs in quantum photonic engineering. Very-Large-Scale Quantum Photonic Processors addresses this challenge on two fronts: First, by leveraging state-of-the-art low-loss silicon photonics and advances in large-scale packaging and control, quantum photonic processors will be scaled-up to tackle problems at the limit of what is classically simulable. Second, by integrating solid-state quantum emitters with silicon photonics a scalable path is put-forth to enable the deterministic generation of photons and strong photon-photon interactions. In concert, a new arsenal of quantum algorithms will be developed specifically for implementation on this new generation of quantum photonic processors, targeting the key application areas of machine learning and quantum simulation.
