Researchers have developed a groundbreaking hybrid quantum error correction technique that combines discrete and continuously variable methods.

This new approach improves the error tolerance and efficiency of quantum computing, offering up to four times the photon loss threshold and 13 times greater resource efficiency. This technique, which is suitable for a variety of systems including optics, superconducting and ion traps, marks a major advance in quantum computing architecture.

Quantum error correction

A major challenge in the implementation of practical quantum computers is the development of “quantum error correction” technology. This technology corrects errors in qubits, which are key components of quantum computing, preventing errors from getting worse during the calculation. Without this fix, quantum computers will not be able to surpass the performance of conventional computers, and so efforts to advance this technology are continuing worldwide.

Pioneering hybrid methods in quantum computing

From the Korea Institute of Science and Technology (KIST), Dr. Sun-Woo Lee and his team at the Quantum Technology Research Center have pioneered the world’s first hybrid quantum error correction technique. This new method works with both discrete variables (DV) and continuous variables (CV), laying the foundation for a fault-tolerant quantum computing architecture.

Quantum error correction is implemented using logical qubits that come in two forms: DV and CV. While major tech companies such as IBM, Google, Quera, and PsiQuantum focus on the DV approach, others such as Amazon (AWS) and Xanadu prefer to use CV. Each method has its own strengths and weaknesses, including complexity and resource efficiency.

Advances in fault-tolerant quantum architectures

KIST researchers have proposed a method to integrate error correction of DV and CV qubits, which were previously developed separately. They developed a fault-tolerant architecture based on hybrid technology and showed through numerical simulations that it combines the advantages of both techniques, enabling more efficient and effective quantum computing and error correction. Particularly in optical quantum computing, the hybrid approach can achieve a photon loss threshold four times higher than existing methods and increase resource efficiency by more than 13 times while maintaining the same level of logic error rates.

Implications for future quantum computing technologies

Dr. from KIST “The hybrid quantum error correction technology developed in this work can be combined not only with optical systems but also with superconductors and ion trap systems,” said Jaehak Lee. Dr. from KIST, who led the research. “This research opens a new direction for the development of quantum computing,” said Sun-Woo Lee. “Hybrid technologies, which combine the advantages of different platforms, are expected to play a critical role in the development and commercialization of large-scale quantum computers.”

Strategic collaboration advances quantum research

KIST signed a memorandum of understanding (MOU) with the University of Chicago last March to collaborate on quantum technology research involving both institutions and Seoul National University. The researchers announced this major achievement in just over a year thanks to international research collaboration, demonstrating the potential to develop fundamental technologies that will lead the world in the highly competitive field of quantum computing. KIST hosts an international collaborative research center to develop fundamental technologies for quantum error correction with partner institutions such as the University of Chicago, Seoul National University, and Canadian quantum computer company Xanadu.