Condensed matter physics has progressed, relying on discoveries of new materials, new phenomena, and new concepts. A good example can be found in the history of research on strongly correlated electron systems, one of the major traditional strengths of ISSP. On the other hand, breakthroughs have often been made at an intersection of various research fields. Aiming at another leap forward, the Quantum Materials Group has been created to promote interdisciplinary studies based on the collaboration between the experimental and theoretical groups beyond the conventional research disciplines. The quantum materials group currently consists of two core groups and twelve joint groups. All the groups vigorously conduct collaborative research to discover novel quantum phases and functional materials in correlated electron/spin systems. The activities include new material synthesis in bulk and thin-film forms and their characterization through state-of-the-art measurement systems. Device fabrication is also carried out for spintronics applications. These experiments are conducted through lively discussion and tight collaboration with theory groups, which search for new topological phases by using an advanced theoretical approach and numerical methods.