  Realistic quantum computing is subjected to noise. A most important frontier
in research of quantum computing is to implement noise-resilient quantum
control over qubits. Dynamical decoupling can protect coherence of qubits. Here
we demonstrate non-trivial quantum evolution steered by dynamical decoupling
control, which automatically suppresses the noise effect. We designed and
implemented a self-protected controlled-NOT gate on the electron spin of a
nitrogen-vacancy centre and a nearby carbon-13 nuclear spin in diamond at room
temperature, by employing an engineered dynamical decoupling control on the
electron spin. Final state fidelities of 0.91 and 0.88 were observed even with
imperfect initial states. In the mean time, the qubit coherence time has been
elongated by at least 30 folds. The design scheme does not require that the
dynamical decoupling control commute with the qubit interaction and works for
general systems. This work marks a step toward realistic quantum computing.
