Robust phase-controlled gates for scalable atomic quantum processors using optical standing waves

A simple scheme is presented for realizing robust optically controlled quan-tum 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 com-patible 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 particu-larly beneficial for quantum gates involving Doppler sensitive optical frequency transitions and provides an all optical route to scaling up atomic quantum processors.

Automated summary

A simple scheme is proposed for robust optically controlled quantum gates in scalable atomic quantum processors. By driving the qubits with optical standing waves, phase-controlled quantum operations can be realized near the antinodes of the standing wave, which are less sensitive to local optical phase and atomic motion compared to travelling wave configurations. The scheme is compatible with robust optimal control techniques and spatial qubit addressing in atomic arrays, enabling phase controlled operations without tight focusing and precise positioning of control lasers. This provides an all optical route to scaling up atomic quantum processors, particularly beneficial for quantum gates involving Doppler sensitive optical frequency transitions.