Scanning Tunneling Microscopy Studies of Magnetic Topological Phases in Layered Eu-Based Compounds

Magnetic topological materials have attracted broad interest as a platform for realizing novel quantum phenomena such as axion electrodynamics, quantum anomalous Hall states, and spin-dependent transport, that could advance next-generation electronic and spintronic technologies. Among them, layered Eu-based compounds (EuIn₂As₂, EuZn₂As₂, EuSn₂As₂) provide a particularly rich setting to study the interplay between magnetism and topology due to their strong Eu²⁺ 4f moments and strong spin orbit coupling. Using scanning tunneling microscopy and spectroscopy (STM/STS) and density functional theory methods, we probe the electronic local density of states and band structure of these materials across their magnetic phase transition temperature. Our work reveals the topologically trivial and nontrivial phases in these compounds, illustrating how subtle variations in composition and magnetic order drive changes in electronic topology. These findings contribute to a broader understanding of magnetic topological systems.