A novel method for extending the frequency frontier in gravitational wave observations is proposed. It is shown that gravitational waves can excite a magnon. Thus, gravitational waves can be probed by a graviton-magnon detector which measures resonance fluorescence of magnons. Searching for gravitational waves with a wave length λ by using a ferromagnetic sample with a dimension l, the sensitivity of the graviton-magnon detector reaches spectral densities, around 5.4 × 10 −22 × ( l λ/2π ) −2 [Hz −1/2 ] at 14 GHz and 8.6 × 10 −21 × ( l λ/2π ) −2 [Hz −1/2 ] at 8.2 GHz, respectively.

The measurement of the direction of WIMP-induced nuclear recoils is a compelling but technologically challenging strategy to provide an unambiguous signature of the detection of Galactic dark matter. Most directional detectors aim to reconstruct the dark-matter-induced nuclear recoil tracks, either in gas or solid targets. The main challenge with directional detection is the need for high spatial resolution over large volumes, which puts strong requirements on the readout technologies. In this paper we review the various detector readout technologies used by directional detectors. In particular, we summarize the challenges, advantages and drawbacks of each approach, and discuss future prospects for these technologies.Comment: 58 pages, 26 figures, accepted by Physics Report