Photoemission perspectives on topological, magnetic and moiré quantum materials

Discovery of topological phase transitions opened one of the most fruitful area in solid state physics and chemistry. While the source of non-trivial topology lies within the bulk of material, the most intriguing consequences, such as topological surface states and Fermi arcs, take place at the surface or interface with "normal" material.  Recently topological materials with their own magnetic and superconducting orders had been realized. Additional degree of freedom at the interface – moiré superlattice – allows to enhance and tune the electronic correlations and could lead to brand-new fundamental phases, such as multiple chiral Majorana modes. In this talk I will show our latest results on topological, magnetic and superconducting  materials and heterostructures focusing on the electronic structure studied by means of angle-resolved photoemission spectroscopy (ARPES). I will report the recent observations of the topological phase transitions in doped MnBi2Te4-family, tuning the electronic structure of NbSe2 by strain and SnSe2 by doping, moiré-induced effects in heterostructures consisting of transition metal dihalides (or noble gases) and topological insulators (Bi2Se3, MnBi2Te4 and others). Combination of the state-of-the-art surface techniques (ARPES, STM, XMCD, AFM,..) and theory allows to unveil the exotic properties of  the quantum materials and heterostructures desired for the next generation of quantum technologies.