In this work we analyze the implementation of a control-phase gate through the resonance between the ∣11⟩ and ∣20⟩ states of two statically coupled transmons. We find that there are many different controls for the transmon frequency that implement the same gate with fidelities around 99.8% (T1=T2∗=17μs) and 99.99% (T1=T2∗=300μs) within a time that approaches the theoretical limit. All controls can be brought to this accuracy by calibrating the waiting time and the destination frequency near the ∣11⟩−∣20⟩ resonance. However, some controls, such as those based on the theory of dynamical invariants, are particularly attractive due to reduced leakage, robustness against decoherence, and their limited bandwidth.
@article{arxiv.2002.10320,
title = {Quantum control of frequency tunable transmon superconducting qubits},
author = {J. J. García-Ripoll and A. Ruiz-Chamorro and E. Torrontegui},
journal= {arXiv preprint arXiv:2002.10320},
year = {2020}
}