  Realizing individual control on single qubits in a spin-based quantum
register is an ever-increasing challenge due to the close proximity of the
qubits resonance frequencies. Current schemes typically suffer from an inherent
trade-off between fidelity and qubits selectivity. Here, we report on a new
scheme which combines noise protection by dynamical decoupling and magnetic
gradient based selectivity, to enhance both the fidelity and the selectivity.
With a single nitrogen-vacancy center in diamond, we experimentally demonstrate
quantum gates with fidelity = 0.9 $\pm$ 0.02 and a 50 kHz spectral bandwidth,
which is almost an order of magnitude narrower than the unprotected bandwidth.
Our scheme will enable selective control of an individual nitrogen-vacancy
qubit in an interacting qubits array using relatively moderate gradients of
about 1 mG/nm.
