Researchers Lift Qubit Coherence Past 250μs With Airbridge-Only Interconnects
Updated
Updated · Quantum Zeitgeist · Jun 17
Researchers Lift Qubit Coherence Past 250μs With Airbridge-Only Interconnects
1 articles · Updated · Quantum Zeitgeist · Jun 17
Summary
Relaxation times above 250 microseconds were achieved in transmon qubits after researchers replaced traditional bandage connections with airbridge-only interconnects in superconducting circuits.
A single-step gray-scale electron-beam lithography process formed mechanically stable airbridges 0.5 to 4 micrometers wide and 5 to 40 micrometers long, cutting fabrication steps and unwanted material interfaces.
Those eliminated interfaces had been a key source of energy dissipation in earlier designs, which typically struggled to exceed 100 microseconds; resonator and qubit tests showed no measurable added electrical loss.
The method is also compatible with niobium and tantalum, but the team has not yet shown it can scale with uniform yield and alignment across the many-qubit architectures needed for fault-tolerant quantum computing.
Do these 'flying' bridges create a new fragility problem when building massive, thousand-qubit quantum computers?
With qubits lasting longer, how much closer are we to a truly useful, error-corrected quantum computer?
As Europe reveals this quantum leap, how will it shift the global tech race and billion-dollar investments led by the US?
Breaking the Millisecond Barrier: Advances in Qubit Coherence and Airbridge Interconnects for Scalable Quantum Computing
Overview
Between 2025 and 2026, major progress was made in extending qubit coherence times, a key step for practical quantum computing. Aalto University achieved reproducible fabrication of high-quality transmon qubits, highlighting Finland’s growing influence in quantum technology. At the same time, Princeton University introduced design improvements that led to substantial gains in qubit coherence, with benefits that scale as quantum systems grow larger. Together, these efforts in refining qubit fabrication and design are pushing the boundaries of qubit stability and performance, bringing the goal of robust, fault-tolerant quantum computers closer to reality.