Improving quantum control of the soft 0-pi qubit through device engineering*

Ideally, 0-Pi qubit is fully protected against both depolarization and dephasing noise. However, realizing it is a difficult task because of the strict device-fabrication constraints. Therefore, soft 0-Pi qubit has been introduced as an alternative, which is achievable with current technology at the expense of weaker flux-noise protection. However, implementing fast qubit control while avoiding leakage is one of the big challenges that soft 0-Pi qubit faces. In this talk, we explore the parameter space of the soft 0-Pi qubit to maximize coherence and gate speed through low-lying Raman transitions. Moreover, we discuss fabrication constraints and technological considerations that could help push the qubit's design beyond the soft 0-Pi qubit.