The standard model of particle physics is the theory describing fundamental interactions in the Universe. It has passed various experimental tests and successfully predicted and explained different phenomena spanning most fields of particle physics. Despite its great success, the standard model has faced some challenges such as the dark matter and the matter-antimatter problems. More than 25% of the total mass-energy in the Universe is invisible dark matter, which has been only identified by its gravitational effects on visible matter and radiation. In the realm of visible matter, the Universe is predominantly composed of matter, not antimatter. Two new physics subjects will be addressed in this talk, including axions and neutrinoless double beta decay. The axion has been introduced to explain the extremely small value of the neutron electric dipole moment and could be a candidate of dark matter. The neutrinoless double beta decay is a promising method to test the Majorana neutrinos which means neutrinos are their own antiparticles. It will result in leptonnumber violation and could provide a possible explanation for leptogenesis which accounts for the matter-antimatter asymmetry in the Universe.
While traditionally physicists have approached these questions using accelerators, I will present novel methods to search for new physics using atomic magnetometers and germanium detectors to address these two questions. Atomic magnetometers have very high sensitivity to magnetic fields, which can be used to probe the effective field induced by new physics such as axions. Germanium detectors have very good energy performance, which can detect the energy deposit by new physics such as the neutrinoless double beta decay, or axions.