2026/02/28 by Christian Križan, Maurizio Toselli, Irshad Ahmad +11 · 1 voice
Computer Science · Physics and Astronomy · #Mechanical and Optical Resonators #Quantum Information and Cryptography #Quantum and electron transport phenomena
paper · doi:10.1088/2633-4356/ae7fe1
openalex publication_date 2026/06/19 · openalex created_date 2026/06/20 · openalex updated_date 2026/08/01
Abstract Josephson junctions are key elements of superconducting quantum technology, serving as the core building blocks of superconducting qubits. We present an experimental study on room-temperature electrical tuning of aluminum junctions, showing that voltage pulses can controllably increase their resistance and adjust the Josephson energy while maintaining qubit quality factors above 1 million. We find that the rate of resistance increase scales exponentially with pulse amplitude during manipulation. Following the manipulation, the resistance increases spontaneously through contributions proportional to both the initial resistance and the preceding manipulation. We show that this spontaneous increase halts at cryogenic temperatures, and resumes again at room temperature. Using our stepwise protocol, we achieve up to a 270% increase in junction resistance, corresponding to a reduction of nearly 2 GHz of the qubit transition frequency. These results establish the achievable range, relaxation behavior, and practical limits of electrical tuning, enabling post-fabrication mitigation of frequency crowding in quantum processors.