  We suggest a test of a central prediction of perturbatively quantized general
relativity: the coherent communication of quantum information between massive
objects through gravity. To do this, we introduce the concept of interactive
quantum information sensing, a protocol tailored to the verification of
dynamical entanglement generation between a pair of systems. Concretely, we
propose to monitor the periodic wavefunction collapse and revival in an atomic
interferometer which is gravitationally coupled to a mechanical oscillator. We
prove a theorem which shows that, under the assumption of time-translation
invariance, this collapse and revival is possible if and only if the
gravitational interaction forms an entangling channel. Remarkably, as this
approach improves at moderate temperatures and relies primarily upon atomic
coherence, our numerical estimates indicate feasibility with current devices.
