Intrinsic high-temperature quantum anomalous Hall effect and tunable magnetic topological phases in XYBi2Te5

By first-principles calculations, we study the magnetic and topological properties of XYBi2Te5-family (X, Y =Mn, Ni, V, Eu) compounds. The strongly coupled double magnetic atom-layers can significantly enhance the magnetic ordering temperature while keeping the topologically nontrivial properties. Particularly, NiVBi2Te5 is found to be a magnetic Weyl semimetal in bulk and a Chern insulator in thin film with both the Curie temperature and magnetic gap well above 77K. Ni2Bi2Te5 exhibits a dynamic axion state above 77K with a magnetic ordering temperature up to room temperature. These results indicate an approach to realize high temperature QAHE and other topological quantum effects for practical applications.