Japanese scientists develop scalable quantum LDPC error correction codes approaching the theoretical hashing bound.
Scientists at the Institute of Science Tokyo have announced a breakthrough in quantum error correction that could bring a large-scale quantum computer closer to reality.The team has developed a new class of quantum low-density parity-check error correction codes that perform close to the hashing bound, the theoretical efficiency limit for quantum error correction.
“Our quantum error-correcting code has a greater than 1/2 code rate, targeting hundreds of thousands of logical qubits,” explained Kenta Kasai, Associate Professor and the main lead on the project.“Moreover, its decoding complexity is proportional to the number of physical qubits, which is a significant achievement for quantum scalability,” he added.Quantum computers have long promised to revolutionize fields like quantum chemistry, cryptography, and large-scale optimization. However, their progress has been stunted due to the fragile nature of qubits.The problem it solvesUsually, qubits tend to lose their state quickly and have short coherence times. Furthermore, operations like gates and measurements introduce high error rates. The current quantum error correction methods require thousands of physical qubits to create just one logical qubit.The new LDPC codes are designed to handle hundreds of thousands of qubits. They have a high coding rate, meaning fewer physical qubits are wasted in creating a logical qubit.This combination of efficiency and scalability could make millions of logical qubits possible, marking a key step towards solving real-world problems.How did they do it?The scientists used photograph LDPC codes, a design that works well for error correction. Further, they used affine permutations, which makes code structures diverse and avoids patterns that slow down decoding.Instead of only binary math, they use non-binary math to carry more information and improve accuracy. Then, these codes were converted to Calderbank-Shor-Steane codes – a well-known type of quantum error correction.To decode errors, they created an efficient method based on the sum-product algorithm, which can fix both types of quantum errors—bit-flip and phase-flip —at the same time. Older codes usually handled only one type at once.Analyzing the resultEven with hundreds of thousands of qubits, they kept the frame error rate as low as 10−4. This result is quite close to the hashing bound – the best performance theoretically possible.“Our quantum LDPC error correction codes can potentially enable quantum computers to scale up to millions of logical qubits,” remarked Kasai.“This will significantly improve the reliability and scalability of quantum computers for practical applications while also paving the way for future research,” he said after the completion of the experiment.The study represents a major step towards fault-tolerant computing for practical applications, which could benefit many fields.This study was recently published in the journal npj Quantum Information.
Japan Quantum Computers Quantum Computing Quantum Processor Qubits Science
United States Latest News, United States Headlines
Similar News:You can also read news stories similar to this one that we have collected from other news sources.
Utah’s Jaxson Dart, once a scrawny Roy High QB, takes over in New YorkHow a Utah high school star became the New York Giants’ new starting quarterback.
Read more »
The New Season: Fall 2025 - The most anticipated new movies, music, TV and moreBe on the lookout for these new entertainment offerings in the coming months, from screens to the stage, from music to the page.
Read more »
Louise Trotter Debuts the New-New Bottega Veneta at Milan Fashion WeekThe newly appointed designer's superpower is an understanding of what working women actually want to wear.
Read more »
I'm a Japanese founder who moved to Bengaluru to grow my startupBusiness Insider tells the global tech, finance, stock market, media, economy, lifestyle, real estate, AI and innovative stories you want to know.
Read more »
With $30 million gift, Wistar Institute opens center dedicated to developing new medicinesThe Wistar Institute's new center will accelerate the process of translating discoveries into new medicines.
Read more »
GBP/JPY slumps to near 199.50 as Japanese Yen outperforms across the boardThe GBP/JPY pair trades 0.4% down to near 199.50 during the European trading session on Monday. The pair falls sharply as weakness in the US Dollar (USD) due to mounting United States (US) government shutdown risks has increased the safe-haven appeal of the Japanese Yen (JPY).
Read more »