Current Status and Future Prospects of Optical Quantum Computing

This paper introduces the principles and implementation of continuous-variable optical quantum computing (CV-OQC) and provides an overview of the current status and challenges of its research and development. The optical approach is considered a strong candidate for realizing large-scale, fault-tolerant quantum computers, as it enables large-scale quantum entanglements to be generated by using optical qubits that retain their quantum nature even at room temperature. Many of the CV-OQC technologies are adapted from existing optical communication technologies. However, numerous technical challenges remain, including the implementation of quantum error correction and cubic phase gate operations for achieving quantum advantage. These challenges span a broad range, from hardware problems to software issues, and they need to be addressed integrally within the control circuitry. Thus, the advancement of CV-OQC necessitates collaboration among research institutions and companies with diverse strengths. Moreover, despite the numerous hurdles, CV-OQC technologies for transmitting and manipulating optical quantum states would also be beneficial to other approaches to quantum computing and communication. Thus, continued research and development in this area would be highly valuable.