Quantum Leap: Achieving New Qubit Performance Records Paves the Way for Practical Quantum Computing Advancements
In a groundbreaking development, researchers at Aalto University in Finland have successfully extended the coherence time for transmon qubits to an unprecedented 1 millisecond. This significant leap forward was published in *Nature Communications* in July 2025.
The coherence time of a qubit, the smallest unit of information for quantum computers, determines how long quantum information can be stored and manipulated before it is lost due to decoherence. Longer coherence times mean more operations can be performed before errors occur, directly improving the practicality and reliability of quantum computers.
This achievement surpasses previous records, where coherence times for transmon qubits had reached roughly 0.6 milliseconds[1][2]. The extended coherence time allows quantum computers to execute more complex computations while keeping error rates manageable. This reduction in the demand for resources dedicated to quantum error correction is a critical step towards building fault-tolerant, scalable quantum systems[1][2][3].
The Quantum Computing and Devices (QCD) group at Aalto University achieved this milestone using high-quality superconducting films. This foundational step towards practical, large-scale quantum computers strengthens Finland’s position as a leader in quantum technology and opens doors to new research opportunities and innovation in the field[2][3].
Recent reports from other groups in June 2025 showed typical coherence times (T1) for transmon qubits around 85–100 microseconds, which are orders of magnitude shorter than the new millisecond benchmark set by Aalto University[4]. This dramatic improvement in coherence time is expected to enable more sophisticated quantum algorithms and accelerate progress toward commercially viable quantum computing.
As the field of quantum computing continues to evolve, alternative approaches for fabricating the physical qubits themselves are being investigated to further improve performance. The ongoing debate about quantum advantage persists, with Google's Sycamore processor featuring 53 qubits, while Quantinuum's processor has 56 qubits[5].
Quantum error correction plays a crucial role in "fighting decoherence more effectively." This process places single, physical qubits into intricate circuits collectively referred to as a "logical qubit." Qubits are extremely sensitive to background noise, leading to data loss in a process called qubit decoherence. Longer coherence times should reduce the amount of time and energy that goes into quantum error correction.
In theory, quantum computers can surpass the computational potential of any classical supercomputer. However, achieving this potential requires significant advancements in various aspects of quantum computing, including qubit fabrication, error correction, and algorithm development. The new result from Aalto University represents one of "probably a hundred or thousand more of these steps" to reach the desired functionality for quantum computers.
[1] https://www.nature.com/articles/s41467-025-31307-z [2] https://www.aalto.fi/en/news/news-articles/2025/07/aalto-university-researchers-set-new-world-record-for-quantum-computing [3] https://www.sciencedaily.com/releases/2025/07/250716102345.htm [4] https://arxiv.org/abs/2506.13241 [5] https://www.google.com/amp/s/www.technologyreview.com/s/615087/google-says-its-quantum-computer-is-100-million-times-faster-than-classical-ones/amp/ [6] https://www.quantinuum.com/news/quantinuum-announces-the-worlds-first-universal-quantum-computer-based-on-the-trapped-ion-quantum-architecture/
- The breakthrough in extending the coherence time of transmon qubits to 1 millisecond by researchers at Aalto University could potentially revolutionize the future of technology and science, as longer coherence times enable quantum computers to execute more complex computations.
- Gizmodo reports on the critical significance of the achievement, stating that the reduction in the demand for resources dedicated to quantum error correction – a result of the extended coherence time – is a crucial step towards building fault-tolerant, scalable quantum systems.
- As the field of quantum computing advances, the new millisecond benchmark set by Aalto University is expected to enable more sophisticated quantum algorithms and accelerate progress towards commercially viable quantum technology, ultimately bringing us closer to outperforming the computational potential of classical supercomputers.
