  In an experiment using the odd calcium isotope 43Ca+ we combine the merits of
a high fidelity entangling operation on an optical transition (optical qubit)
with the long coherence times of two 'clock' states in the hyperfine ground
state (hyperfine qubit) by mapping between these two qubits. For state
initialization, state detection, global qubit rotations and mapping operations,
errors smaller than 1% are achieved whereas the entangling gate adds errors of
2.3%. Based on these operations, we create Bell states with a fidelity of
96.9(3)% in the optical qubit and a fidelity of 96.7(3)% when mapped to the
hyperfine states. In the latter case, the entanglement is preserved for 96(3)
ms, exceeding the duration of a single gate operation by three orders of
magnitude.
