Direct search for light dark matter with quantum detectors

Due to observations of celestial phenomena, it is evident that only about 37% of the matter in our universe is visible. The majority of matter appears to be dark or does not interact with light and has not been directly observed till now. However, the analysis and simulations of observations strongly indicate that the milky way and our solar system is completely populated with dark matter particles. For this reason, the detection and characterization of such dark matter candidates on earths surface is feasible and presents one of the major challenges of modern physics. Most former experiments concentrated on the search for dark matter particles with heavy masses. To detect those particles, the interaction processes between dark matter with e.g. up to some 1000 kg of liquefied noble gas was studied. But those experiments could just exclude different mass ranges and many underlying models of theoretical physics have been disproved by particle accelerator experiments in recent years. Thus, the search for light dark matter particles became more attractive nowadays. The lighter the particles become, the more of them have to exist. As a consequence, light dark matter experiments need a significant smaller amount of sensitive mass of some kg to detect a reasonable amount of interactions or exclude a further parameter space. For this reason, we propose to use highly specified, low noise silicon detectors to search for light dark matter candidates. The interaction of a dark matter particle with the silicon is expected to excite only some electrons, which are weakly bound to the silicon atoms. In order to measure this tiny interaction, those detectors are required to be sensitive to signals as small as a single electron. The development and operation of these very complex devices require extensive studies and preparation. For instance, background events caused by impurities or thermally exited electrons have to be identified and avoided or reduced in upgraded sensors in order to lay the base for further progress in the direct search for dark matter.