New sensor technologies have enabled dark matter detectors to search for low energy events, expected from recoils of light dark matter particles. However, the sensitivity of these detectors is currently limited by an unidentified background with a steeply rising spectrum towards low energy, called the low energy excess. In this project we aim to identify the source of this excess. We will utilize molecular dynamics and density functional theory simulations to uncover the atom scale physics relevant in the energy scales of interest. We will identify the mechanisms that trigger the energy release from lattice defects that could explain the low energy excess. These results will allow to mitigate the problem and to extend the search of dark matter towards the unexplored low mass region.

2025

2029