Physicists at Aalto University in Finland have achieved a groundbreaking milestone in quantum computing. Published on July 8, 2025, their research in Nature Communications reveals a transmon qubit coherence time reaching a millisecond. This achievement far exceeds previous records and represents a significant advancement in computational technology.
The newly recorded coherence time, a critical measure for quantum computing efficiency, allows for more complex computations and reduces the need for error correction. Previously, echo coherence measurements peaked at about 0.6 milliseconds. The extended coherence time means quantum computers can perform more operations without errors, a crucial step towards noiseless quantum computing.
Breakthrough in Quantum Science
Ph.D. student Mikko Tuokkola, who led the measurements and analysis, highlighted the significance of the results. “We measured an echo coherence time for a transmon qubit that reached a millisecond at its peak, with a median of half a millisecond,” he stated. This median reading also surpasses existing records, showcasing the advancements made by the team.
Supervised by Dr. Yoshiki Sunada, a postdoctoral researcher now at Stanford University, Tuokkola’s work was supported by the Quantum Computing and Devices (QCD) research group at Aalto University. The group is part of the Academy of Finland Center of Excellence in Quantum Technology and the Finnish Quantum Flagship.
Finland’s Leadership in Quantum Technology
The successful fabrication of high-quality transmon qubits in an academic environment underscores Finland’s leadership in the field. “Achieving such results in a cleanroom accessible for academic research strengthens Finland’s position in quantum science and technology,” Dr. Sunada explained.
The QCD group, utilizing high-quality superconducting film from the Technical Research Center of Finland, demonstrated the potential of Finland’s national research infrastructure, Micronova cleanrooms at OtaNano. According to Professor Mikko Möttönen, head of the QCD group, “This landmark achievement has solidified Finland’s standing as a global leader in quantum technology.”
The study’s detailed methodology aims to enable reproducibility by research groups worldwide, pushing the boundaries of what is possible with future quantum computers. More information can be found in the full research article, “Methods to achieve near-millisecond energy relaxation and dephasing times for a superconducting transmon qubit,” available through Nature Communications and arXiv.
