Quantum frequency interferometry: With applications ranging from gravitational wave detection to dark matter searches

Richard Howl, Ivette Fuentes

Research output: Contribution to journalArticlepeer-review


We introduce a quantum interferometric scheme that uses states that are sharp in frequency and delocalized in position. The states are frequency modes of a quantum field that is trapped at all times in a finite volume potential, such as a small box potential. This allows for significant miniaturization of interferometric devices. Since the modes are in contact at all times, it is possible to estimate physical parameters of global multimode channels. As an example, we introduce a three-mode scheme and calculate precision bounds in the estimation of parameters of two-mode Gaussian channels. This scheme can be implemented in several systems, including superconducting circuits, cavity-QED, and cold atoms. We consider a concrete implementation using the ground state and two phononic modes of a trapped Bose–Einstein condensate. We apply this to show that frequency interferometry can improve the sensitivity of phononic gravitational waves detectors by several orders of magnitude, even in the case that squeezing is much smaller than assumed previously, and that the system suffers from short phononic lifetimes. Other applications range from magnetometry, gravimetry, and gradiometry to dark matter/energy searches.
Original languageEnglish
Article number014402
JournalAVS Quantum Science
Issue number014402
Publication statusPublished - 23 Jan 2023

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