  A qubit made up of an ensemble of atoms is attractive due to its resistance
to atom losses, and many proposals to realize such a qubit are based on the
Rydberg blockade effect. In this work, we instead consider an experimentally
feasible protocol to coherently load a spin-dependent optical lattice from a
spatially overlapping Bose--Einstein condensate. Identifying each lattice site
as a qubit, with an empty or filled site as the qubit basis, we discuss how
high-fidelity single-qubit operations, two-qubit gates between arbitrary pairs
of qubits, and nondestructive measurements could be performed. In this setup,
the effect of atom losses has been mitigated, the atoms never need to be
removed from the ground state manifold, and separate storage and computational
bases for the qubits are not required, all of which can be significant sources
of decoherence in many other types of atomic qubits.
