Magnetic photocurrent in even-layered topological antiferromagnet MnBi₂Te₄

MnBi₂Te₄ is a magnetic topological insulator that holds rich physical properties down to their 2D limit. Each septuple layer consists of a Bi₂Te₃ layer and a MnTe layer, which give rise to its topology and pristine magnetism, respectively. Moreover, as the magnetic moments couple antiferromagnetically between adjacent septuple layers, the spin texture breaks the inversion symmetry of even-layered MnBi₂Te₄ and leads to magnetic photocurrents that have been rarely studied before. In this talk, I will present our experimental study of the optoelectronic responses in even-layered MnBi₂Te₄. We observe an intrinsic photocurrent that can be controlled by external electrical and magnetic fields. I will also discuss how the magnetic photocurrent could also decode MnBi₂Te₄’s quantum geometrical structures.