Entanglement-Enhanced Optomechanical Sensor Array for Dark Matter Searches*

The nature of dark matter (DM) is one of the most important open questions in modern physics. The search for DM is challenging since, besides gravitational interaction, it feebly interacts with ordinary matter. We propose entanglement-enhanced optomechanical sensing systems to assist the search for DM with mechanical devices. To assess the performance of our setup, we adopt the integrated sensitivity, which is suitable for broadband sensing as it quantifies the bandwidth-sensitivity tradeoff of the system. We show that, by coherently operating the mechanical sensor array and utilizing multi-partite entanglement between the optical fields, the array has a scaling advantage over independent sensors as well as a performance boost due to entanglement. The in our scheme is not necessarily due to the amount of light that impinges on a single mechanical oscillator within the array but, rather, is a consequence of the quantum correlations between the optical fields that impacts the mechanics as a collective. Such an improvement is achievable with off-the-shelf experimental components.