Entanglement generation between atoms and mechanical resonators: from magnetic to gravitational interactions

A tremendous amount of recent effort has focused on developing hybrid systems of quantum sensors coupled to a dynamical macroscopic mass. These systems can serve as a versatile testbed for measuring the low energy quantum mechanical behavior of macroscopic masses and investigating the integration of quantum mechanics with gravity. This work builds on a recent experimental proposal for entangling a trapped atom interferometer with a test mass to elucidate the behaviors of certain quantum theories of gravity [https://doi.org/10.1103/PRXQuantum.2.030330].

Using an atom interferometer where atoms are held in an optical lattice can allow for minute scale interactions with the test mass [https://arxiv.org/abs/2301.13315]. Additionally, a diamagnetic test mass enables tuning the nature of the coupling. I will discuss our efforts to optimize the performance of entangling protocols that use such a magnetic interaction as a complement to the gravitational interaction, and whether such entanglement may be accessible in future experiments. Critically, our approach relies upon leveraging the atoms in the different interferometric paths to create non-classical states of a mechanical system. We aim to use a low-frequency oscillator with an unprecedented mechanical quality factor. This may lead to mechanical-atom entangled states which may be particularly sensitive to effects like gravitational decoherence.