  High-fidelity control of quantum systems is crucial for quantum information
processing, but is often limited by perturbations from the environment and
imperfections in the applied control fields. Here, we investigate the
combination of dynamical decoupling (DD) and robust optimal control (ROC) to
address this problem. In this combination, ROC is employed to find robust
shaped pulses, wherein the directional derivatives of the controlled dynamics
with respect to control errors are reduced to a desired order. Then, we
incorporate ROC pulses into DD sequences, achieving a remarkable improvement of
robustness against multiple error channels. We demonstrate this method in the
example of manipulating nuclear spin bath via an electron spin in the NV center
system. Simulation results indicate that ROC based DD sequences outperform the
state-of-the-art robust DD sequences. Our work has implications for robust
quantum control on near-term noisy quantum devices.
