In this talk, I would like to introduce two experimental projects; one is measurement of neutrinos’ unknown properties, and the other is detection of axion which is one of the prime candidate particles of dark matters. Both experiments utilize a process in which ensemble of atoms are excited coherently. The former experiment, named SPAN (Spectroscopy of Atomic Neutrino), aims to systematically determine remaining important neutrino parameters such as the absolute neutrino mass value, distinction of Majorana neutrino from Dirac neutrino, and CP violating phases. To realize this goal, an experiment is in progress to observe a de-excitation process that emits a pair of neutrino and photon from metastable atomic states. One of the key concepts of the project is ``macro-coherent amplification principle" which should amplify otherwise small atomic neutrino rate to observable levels. Recently thos principle has been tested experimentally with a two-photon QED process. The result shows that, thanks to generated coherence, the observed rate is 10¹⁸ larger than that of the spontaneous rate. Current status and future prospects of the SPAN project are presented in this talk along with the newly proposed axion search experiment.