The semiconductor industry, which supports our daily lives, is comprised of a variety of technologies, including ultra-high quality crystal growth technology, high-frequency circuits, and optical technology. We study the physics of electrons, holes, excitons, nuclear spins, etc. interwoven by quantum mechanics on the platform of ultra-pure semiconductor devices and novel materials. Recently, we are focusing on actualizing a toy model, which is mathematically equivalent to the Big Bang and black holes (quantum universe), on a semiconductor chip. We are aiming to explore new physics through collaborative research with a wide range of researchers in the fields of high-energy physics, cosmology, quantum information, condensed matter theory, and materials science.