Dynamical decoupling represents an active approach towards the protection of quantum memories and quantum gates. Because dynamical decoupling operations can interfere with system's own time evolution, the protection of quantum gates is more challenging than that of quantum states. In this work, we put forward a simple but general approach towards the realization of higher-order protection of quantum gates. The central idea of our approach is to engineer (hence regain the control of) the quantum gate Hamiltonian in coordination with higher-order dynamical decoupling sequences originally proposed for the protection of quantum memories. In our computational examples presented for illustration, the required engineering can be implemented by only quenching the phase of an external driving field at particular times.
Comment: 5 pages, 2 figures. Improved discussions