[Market Pulse] The Era of Quantum Advantage Is Rapidly Approaching

A New Phase Expected from the Integration of Quantum and Supercomputers
Hardware, Infrastructure, and Algorithms Are Key

In June 2025, IBM and Japan's RIKEN (Institute of Physical and Chemical Research) made an announcement marking a significant turning point in the history of quantum computing. IBM's highest-performance quantum computer, Quantum System Two, was directly connected and began operation with Fugaku, one of the world's most powerful supercomputers.

This announcement goes beyond a mere technological advancement, as this system could become a decisive milestone in achieving quantum advantage. In 2023, IBM demonstrated the practical scientific utility of quantum computers by performing complex calculations with its Quantum Eagle system, which is based on a 127-qubit processor-calculations that traditional supercomputers could not handle. This stage is referred to as "quantum utility."

Quantum advantage is a concept that goes a step further: it is achieved when a quantum computer can perform calculations more accurately, more quickly, or more cost-effectively than conventional supercomputers. Once this stage is reached, quantum computing will become a practical technology used to solve real-world industrial and societal problems, rather than just serving as a research tool. This is expected to usher in a full-fledged quantum era across various fields.

IBM anticipates that the first demonstration of quantum advantage will occur by the end of 2026. Rather than expecting quantum computers alone to achieve this milestone, IBM sees a hybrid approach-maximizing performance by combining quantum computers with conventional supercomputers-as a more realistic path. In other words, "the combined performance of quantum computers and supercomputers" will surpass "the performance of supercomputers alone."

This approach is based on the outlook that quantum computing will not entirely replace existing supercomputing, but will instead develop in a direction that creates synergy by combining their respective strengths. This is called "quantum-centric supercomputing," and it represents a new paradigm in which quantum and supercomputing systems share the workload of solving complex problems, going beyond parallel processing with graphics processing units (GPUs). For example, supercomputers could handle large-scale data preprocessing and optimization tasks, while quantum computers tackle quantum-mechanical calculations that are difficult to solve using conventional methods.

This structure could have a significant impact, especially in fields such as materials science, chemistry, and drug discovery. In fact, IBM and RIKEN recently demonstrated the practical scientific value of this integrated system through research that accurately modeled the electronic structure of iron pyrite (FeS₂)-a problem previously thought to require fault-tolerant quantum computers.

Meanwhile, quantum advantage must be rigorously verified. In the future, various research teams will claim to have achieved quantum advantage; these claims will be met with both support and rebuttal, eventually leading to scientific consensus. Therefore, quantum advantage is not a single event, but is expected to be realized gradually through multiple experiments and verifications.

Three key elements are needed for this process: high-performance quantum hardware systems; infrastructure that can integrate the resources of conventional supercomputing and quantum systems to run programs; and accurate, useful quantum algorithms and circuit execution technologies. In particular, the third element still requires significant development, and it is hoped that Korea's outstanding research institutions and universities will play a leading role in this area.

Even after quantum advantage is demonstrated, the journey to develop practical applications for quantum computing will continue. This will remain true even after the advent of fault-tolerant quantum computers capable of error correction. Just as conventional computing technologies have evolved over decades and continue to advance to this day, quantum computing will also undergo a long-term development process. This journey is not a sprint, but a marathon, and now is the best time to stand at the starting line.

Baek Hanhee, Director of IBM Quantum Algorithm Center