We present an interferometric sensor for investigating macroscopic quantum mechanics on a table-top scale. The sensor consists of pair of suspended optical cavities with a finesse in excess of 100,000 comprising 10 g fused-silica mirrors. In the current room-temperature operation, we achieve a peak sensitivity of \SI{0.5}{\fmasd} in the acoustic frequency band, limited by the readout noise. With additional suppression of the readout noise, we will be able to reach the quantum radiation pressure noise, which would represent a novel measurement of the quantum back-action effect. Such a sensor can eventually be utilised for demonstrating macroscopic entanglement and testing semi-classical and quantum gravity models.
@article{arxiv.2402.00821,
title = {A High-Finesse Suspended Interferometric Sensor for Macroscopic Quantum Mechanics with Femtometre Sensitivity},
author = {Jiri Smetana and Tianliang Yan and Vincent Boyer and Denis Martynov},
journal= {arXiv preprint arXiv:2402.00821},
year = {2024}
}