  A simple scheme is presented for realizing robust optically controlled
quantum gates for scalable atomic quantum processors by driving the qubits with
optical standing waves. Atoms localized close to the antinodes of the standing
wave can realize phase-controlled quantum operations that are potentially more
than an order of magnitude less sensitive to the local optical phase and atomic
motion than corresponding travelling wave configurations. The scheme is
compatible with robust optimal control techniques and spatial qubit addressing
in atomic arrays to realize phase controlled operations without the need for
tight focusing and precise positioning of the control lasers. This will be
particularly beneficial for quantum gates involving Doppler sensitive optical
frequency transitions and provides an all optical route to scaling up atomic
quantum processors.
