Co-designing Transmon devices for control with simple pulses

A challenge in applying results from optimal control theory is to implement potentially complex pulse shapes. In this work, we limit our parametrization to simple pulses and investigate model regimes for superconducting qubits. We tweak the pulses and model parameters, such as frequencies and couplings, for a simulation of a two qubit chip together with the controls to derive single and two-qubit gates.

To ensure the flexibility in creating entangling gates, we employ perfect entangler theory and compare settings with and without an additional tunable coupler. We find that the "straddling" regime [1] is still promising, however hard to realize with the simple control scheme.

[1] M. H. Goerz, F. Motzoi, K. B. Whaley, and C. P. Koch, npj Quantum Information 3, 37 (2017)