  Single qubit rotations and two-qubit CNOT operations are crucial ingredients
for universal quantum computing. While high fidelity single qubit operations
have been achieved using the electron spin degree of freedom, realizing a
robust CNOT gate has been a major challenge due to rapid nuclear spin dephasing
and charge noise. We demonstrate an efficient resonantly-driven CNOT gate for
electron spins in silicon. Our platform achieves single-qubit rotations with
fidelities >99%, as verified by randomized benchmarking. Gate control of the
exchange coupling allows a quantum CNOT gate to be implemented with resonant
driving in ~200 ns. We use the CNOT gate to generate a Bell state with 75%
fidelity, limited by quantum state readout. Our quantum dot device architecture
opens the door to multi-qubit algorithms in silicon.
