Experimental system to detect the electromagnetic response of high-frequency gravitational waves

Abstract

The mechanical tidal effects of gravitational waves (GWs) in the low- and middle-frequency bands, typically from dozens to hundreds of Hz, have been detected by the LIGO-Virgo-KAGRA ground laser interferometers. To implement the detection of the GWs in the higher-frequency bands (such as the MHz band and the higher ones), predicted by a series of theoretical models in astrophysics and cosmology, we propose here an experimental system to probe their electromagnetic (EM) responses (EMRs). The system mainly consists of a modulated high magnetic field and the weak-light detection techniques (such as single-photon detectors). Physically, when the high-frequency GWs pass through such a modulated high magnetic field, the first-order EMR signals, rather than the second-order ones generated by the inverse Gertsenshtein effects, are induced and can be detected by the current weak-light detection techniques. Interestingly, by considering the influences from the main noises, i.e., the thermal and shot ones, we show that the sensitivity of the proposed system could be utilized to implement the detection of the relic GWs (predicted by the well-known Big Bang model) in the MHz and GHz bands, depending on the frequency of the applied alternating magnetic field. Hopefully, such an experimental system can be built to detect the EMRs of the GWs for testing the relevant gravitational models.