Simultaneous Resonant and Broadband Detection of Ultralight Dark Matter and High-Frequency Gravitational Waves via Cavities and Circuits

TL;DR

This paper introduces a novel cavity and circuit-based detection method that uses auxiliary modes and parametric couplings to achieve broadband sensitivity for ultralight dark matter and high-frequency gravitational waves, overcoming the narrow bandwidth limitation of traditional resonators.

Contribution

The authors develop a new broadband detection scheme employing auxiliary modes and parametric couplings, enabling simultaneous resonant and broadband detection without tuning.

Findings

Achieves effective bandwidth comparable to resonant frequency.

Allows probing multiple source frequency orders with high sensitivity.

Enables deeper parameter space exploration within the same integration time.

Abstract

Electromagnetic resonant systems, such as cavities and LC circuits, are widely used to detect ultralight boson dark matter and high-frequency gravitational waves. However, the narrow bandwidth of single-mode resonators necessitates multiple scan steps to cover broad frequency ranges. By incorporating a network of auxiliary modes via beam-splitter-type and non-degenerate parametric couplings, we enable broadband detection with an effective bandwidth of each scan matching the order of the resonant frequency, while maintaining a strong signal response. In heterodyne upconversion detection, where a background cavity mode transitions into another due to a potential background source, multiple orders of the source frequency can be probed with high sensitivity without tuning the cavity frequency. Consequently, our method allows for significantly deeper exploration of the parameter space within the same integration time compared to single-mode detection.