Dynamic compensation for pump-induced frequency shift in Kerr-cat qubit initialization
Yifang Xu, Ziyue Hua, Weiting Wang, Yuwei Ma, Ming Li, Jiajun Chen, Jie Zhou, Xiaoxuan Pan, Lintao Xiao, Hongwei Huang, Weizhou Cai, Hao Ai, Yuxi Liu, Chang‐Ling Zou, Luyan Sun · Physical Review Applied · 2025
The noise-biased Kerr-cat qubit is an attractive candidate for fault-tolerant quantum computation; however, its initialization faces challenges due to the squeezing pump-induced frequency shift. Here we propose and demonstrate a dynamic compensation method to mitigate the effect of pump-induced frequency shift during the Kerr-cat qubit initialization. Using a nonlinearity-engineered multiloop superconducting quantum interference device, we realize a stabilized Kerr-cat qubit and validate the advantages of the dynamic compensation method by increasing the initialization fidelity from 57% to 78%, with a projected fidelity of 91% after exclusion of state preparation and measurement errors. Our results not only advance the practical implementation of Kerr-cat qubits, but also provide valuable insights into the fundamental adiabatic dynamics of these systems. This work is valuable for scalable quantum processors that leverage the noise-biased properties of Kerr-cat qubits.