Scheme for directly observing the noncommutativity of the position and the momentum operators with interference

Although noncommutativity of a certain set of quantum operators (e.g., creation and annihilation operators and Pauli spin operators) has been shown experimentally in recent years, the commutation relation for the position and the momentum operators has not been directly demonstrated to date. In this paper we propose and analyze an experimental scheme for directly observing the noncommutativity of the position and the momentum operators using single-photon quantum interference. While the scheme is studied for the single-photon state as the input quantum state, the analysis applies equally to matter-wave interference, allowing a direct test of the position-momentum commutation relation with a massive particle.