Princeton University Dark Cosmos Seminar

Abstract: As the search space for light dark matter (DM) has shifted to sub-GeV DM candidate partcles, increasing attention has turned to solid state detectors built from “quantum materials”. While traditonal solid state detector targets (e.g. Si or Ge) have been utilized in searches for dark matter (DM) for decades, more complex, anisotropic materials with narrow bandgaps are desirable for detecting the largely unexplored space of sub-MeV dark matter through DMelectron scattering and absorption channels. In order to determine if a novel target material can expand the search space for light DM it is necessary to determine the projected reach of a dark matter search conducted with that material in the DM mass – DM-electron scattering cross-section parameter space. Conventional solid state targets generally have a wealth of experimental measurements on which to draw to determine their projected reach for DMelectron scattering experiments. The next-generation quantum materials intended for sub-MeV DM detection, however, often don’t have this luxury. Ab initio electronic structure calculations, a staple in condensed matter research, have become an invaluable tool in predicting the projected experimental reach of emerging quantum material targets. Here I will present a theoretical framework for leveraging ab initio electronic structure calculations to predict projected experimental reach via calculations of the dielectric function. I will discuss the challenges in achieving accurate prediction of experimental reach and present calculations of the projected reach and dielectric function for traditional and emerging quantum material DM detector targets.