Extensible universal photonic quantum computing with nonlinearity

TL;DR

This paper presents an extensible photonic quantum computing platform that integrates scalable linear optics with nonlinear modules, enabling universal gates, quantum state generation, and simulation of complex many-body dynamics.

Contribution

The authors introduce a scalable architecture combining linear and nonlinear photonic components, enabling universal quantum gates and advanced quantum simulations.

Findings

Demonstrated quasi-deterministic generation of Gottesman-Kitaev-Preskill states

Simulated Bose-Hubbard model dynamics with photonic hardware

Established a pathway for fault-tolerant photonic quantum computing

Abstract

Universal quantum computing requires an architecture that supports both linear circuits and, crucially, strong nonlinear resources. For quantum photonic systems, integrating such nonlinearities with scalable linear circuitry has been a major bottleneck, leaving most optical experiments without nonlinear operations and, consequently, incapable of achieving universality. Here, we report an extensible photonic computer that supports a universal gate set by seamlessly combining fully programmable, scalable linear optical networks with integrated nonlinear modules. This platform enables a broad range of quantum computing and simulation tasks. We demonstrate the quasi-deterministic generation of optical Gottesman-Kitaev-Preskill states, which are essential resources for bosonic error correction, yet had previously been realized only probabilistically. Furthermore, we simulate complex many-body quantum dynamics, exemplified by the Bose-Hubbard model. Such quantum simulation tasks have long been considered beyond the reach of photonic hardware limited to linear operations. These capabilities, enabled by our extensible architecture, establish a viable route towards photonic quantum simulation and fault-tolerant quantum computing.