Research and Business Trends in Fault-Tolerant Quantum Computers: Expectations for Surface Science and Vacuum Engineering

Fault-tolerant quantum computers (FTQCs) are expected to surpass classical computers in solving problems such as integer factorization, quantum chemistry, machine learning, and quantum simulations. Recent progress in quantum error correction, including the realization of logical qubits, has accelerated the transition from noisy intermediate-scale quantum devices (NISQ) toward practical FTQCs. Among various hardware approaches, superconducting qubits and neutral atom qubits are currently leading candidates, with rapid advances reported by major companies and research institutes. However, achieving scalable FTQCs requires overcoming critical technological challenges in materials, device fabrication, and system integration. In this context, surface science and vacuum engineering play pivotal roles. High-quality thin films, defect-free interfaces, ultra-high vacuum environments, and advanced cleaning and bonding techniques directly determine qubit coherence and reliability. This article reviews the current research and business trends in FTQCs and highlights the crucial contributions expected from the surface science and vacuum engineering communities.