Detection of gravitational waves using parametric resonance in Bose-Einstein condensates

An interesting proposal for detecting gravitational waves involves quantum metrology of Bose-Einstein condensates (BECs). We consider a forced modulation of the speed of sound of a BEC, whose modulation frequency matches that of an incoming continuous gravitational wave. The speed of sound modulation induces parametric resonance in the BEC, which in turn enhances sensitivity of the BEC to gravitational waves. We find that such a BEC detector could potentially be used to detect gravitational waves across several orders of magnitude in frequency, with the sensitivity depending on the speed of sound, size of the condensate, and frequency of the phonons. We discuss the sensitivity of a possible BEC experiment and comment on the current technological limitations. We also comment on the noise sources as well as what is necessary for such a detector to become feasible.