Superconducting Levitated Detector of Gravitational Waves

Abstract

A magnetically levitated mass couples to gravity and can act as an effective gravitational wave detector. We show that a superconducting sphere levitated in a quadrupolar magnetic field, when excited by a gravitational wave, will produce magnetic field fluctuations that can be read out using a flux tunable microwave resonator. With a readout operating at the standard quantum limit, such a system could achieve broadband strain noise sensitivity of h≲10−20/Hz for frequencies of 1 kHz–1 MHz, opening new corridors for astrophysical probes of new physics. Published by the American Physical Society 2025