A consortium led by Matti Heikinheimo from the Particle Cosmo group received major funding from the Finnish Research Council for the period 09/2025-08/2029. With the other principal investigator, Kai Nordlund from University of Helsinki, the project aims to understand the mechanisms that cause the low energy excess observed in phonon based cryogenic dark matter detectors. This background is currently the most important limiting factor for increasing the sensitivity of dark matter searches towards lower energy and lighter dark matter mass. Our goal is to understand the atom scale physics that sources the excess events and to find ways to mitigate it. Working towards this goal, the project will also produce better understanding of the behavior of the detector materials at cryogenic temperatures and an improved model of the detector response to low energy scattering events, allowing for increased accuracy in the interpretation of the data these detectors produce.