Key technologies toward ultra-fast optical quantum computers

Quantum computers harnessing the principles of quantum mechanics hold the potential to outperform classical systems. Continuous-variable quantum information processing with light offers advantages such as THz-order clock frequencies, scalability via temporal multiplexing, and compatibility with ultra-fast optical communication technologies. This type of quantum computer can be described as an ultra-fast analog quantum computer, making it particularly well-suited for applications involving continuous variables, such as neural networks and optimization problems. However, challenges in universal computation and error correction persist due to weak light-matter interactions. This presentation introduces our advancements in optical quantum computing using waveguide optical parametric amplifiers (OPAs) and non-Gaussian quantum state generation with photon-number resolving detectors (PNRDs). We also propose an all-optical scheme leveraging OPAs to achieve fault-tolerant quantum computing, enabling logical qubit generation and clock frequencies exceeding THz.