The Rise of Optical Quantum Computing

The realm of quantum computing has been predominantly dominated by gate-based quantum computers. These devices utilize physical components, such as superconducting circuits, to control qubits and function in a manner similar to traditional classical computers. However, the Optical Quantum Computing Research Team at the RIKEN Center for Quantum Computing has been venturing into a different realm with their research on measurement-based quantum computing.

In contrast to gate-based quantum computers, measurement-based quantum computers process information using a complex quantum state known as a cluster state, which involves entangled qubits. The team at RIKEN has been exploring the potential of utilizing light to create measurement-based quantum computers, which may have greater scalability than their gate-based counterparts.

A significant advantage of measurement-based quantum computers is their programmability in optical systems. This implies that operations can be altered simply by changing the measurement, making it easier to adapt compared to the hardware changes required in gate-based systems.

The Optical Quantum Computing Research Team, in collaboration with other institutions, has recently achieved noteworthy progress in the field of measurement-based quantum computing with the development of nonlinear feedforward technology. This technological advancement has facilitated the implementation of a wider range of potential gates in optical quantum computers.

Previously, the team faced practical challenges in achieving nonlinear quadrature measurement. However, through the use of complex optics, special electro-optic materials, and ultrafast electronics, they were able to overcome these obstacles. The team effectively utilized digital memories to precompute and record the desired nonlinear functions, enabling the transformation of optical signals into electrical ones.

The speed and flexibility of the nonlinear feedforward technique hold great promise for the future of optical quantum computing. With the ability to synchronize the output with the optical quantum state, the team aims to apply this technology to practical measurement-based quantum computation and quantum error correction. Furthermore, they aspire to further enhance the speed of nonlinear feedforward for high-speed optical quantum computation.

The research conducted by the Optical Quantum Computing Research Team has been published in Nature Communications, demonstrating their breakthroughs in the field of measurement-based quantum computing. This advancement brings optical systems to the forefront as a promising candidate for quantum-computer hardware, despite the prevailing popularity of superconducting circuit-based approaches.

As the world of quantum computing continues to evolve, the innovative work of the team at RIKEN is evidence of the potential of measurement-based quantum computing and its role in shaping the future of quantum technology.