Oral: Expanded Parameter Search of Alternating-Bias Assisted Annealing (ABAA)

A recent study showed that JJs subjected to gentle heating and alternating-polarity voltage pulses exhibit systematic improvements in qubit frequency control and qubit coherence times (Pappas et al., 2024). We are interested in understanding how experimental parameters (voltage, temperature, pulse number, and duration) impact the JJs chemically and structurally, and how these changes translate to qubit performance. Specifically, ABAA may allow us to tune qubit frequencies of packaged devices without changing their coherence time or gate fidelity. With our ABAA process, we consistently observe ΔRn (%) at least three times of that previously reported. We also observed asymptotic behavior by 12,000 pulses with over 130% change in Rn. Through this work, we have observed ABAA to be a highly tunable process with a strong dependence on temperature and voltage amplitude.