  Experiments witnessing the entanglement between two particles interacting
only via the gravitational field have been proposed as a test whether gravity
must be quantized. In the language of quantum information, a non-quantum
gravitational force would be modeled by local operations with classical
communication (LOCC), which cannot generate entanglement in an initially
unentangled state. This idea is criticized as too constraining on possible
alternatives to quantum gravity. We present a parametrized model for the
gravitational interaction of quantum matter on a classical spacetime, inspired
by the de Broglie-Bohm formulation of quantum mechanics, which results in
entanglement and thereby provides an explicit counterexample to the claim that
only a quantized gravitational field possesses this capability.
