GHz spectroscopy on a rare-earth quantum magnet

In this report, spectroscopy was used to track the energy of different states in a LiHoF4 sample around its critical temperature. The experimental setup consist of a Cooper cavity with the sample, an antenna and a resonator inside. This cavity is attached to a probe and put inside a cooled well and a transverse magnetic field. Two different frequency ranges were examined around, f0 = (1.18732 0.00001) Ghz and f0 = (3.32940 0.00001) Ghz. The energy difference between states was successfully tracked for different temperatures thanks to the Q factor plots. However, the lack of sufficient data points and the unexpected behaviour around Tc (there are no gaps and no discontinuities), implies that this is only the beginning of this experiment and more time and measurements is needed to claim reasonable results.