The semiconductor industry that supports modern life is based on a variety of advanced technologies, including ultra-high quality crystal growth and nano-device fabrication. Taking advantage of this technology, we create devices using ultra-high quality semiconductors and novel functional materials. These devices are the stage on which we conduct experiments to explore the novel physics of solid-state particles and quasi-particles such as electrons, spins, holes, excitons and nuclear spins, revealing the essence of quantum mechanics. Understanding the behavior of such particles informs the future technologies of our modern world, and also aids in explaining the fundamental physics of nature. By collaborating with researchers from a variety of fields, such as materials science, solid-state experiment and theory, particle theory and cosmology, we are applying our research to a wide frontier of exciting novel questions.