Thickness Dependence of Electronic Properties of Topological Antiferromagnet MnBi<sub>2</sub>Te<sub>4</sub> Films
ORAL
Abstract
The prerequisite for the realization of the quantum anomalous Hall (QAH) state is an interplay between topology and magnetism. More recently, MnBi2Te4 was experimentally demonstrated to be a material in which the topological and magnetic states intrinsically coexist. The QAH and axion insulator states were predicted in thin films of MnBi2Te4 when the number of layers is odd and even, respectively. Here, we synthesized MnBi2Te4 thin films with thicknesses down to one layer using molecular beam epitaxy (MBE) and systematically studied the thickness dependence of electronic properties. Both Hall and Magneto-Optical Kerr Effect measurements show a clear ferromagnetic hysteresis in the one-layer sample. For films thicker than one layer, similar to the exfoliated MnBi2Te4 devices, the samples show a small ferromagnetic hysteresis loop at the low magnetic field and spin flop transitions at the high magnetic field. We also found the Hall resistance under zero magnetic field displays an odd/even oscillation, i.e., the samples with odd (even) layers exhibit an anomalous Hall (AH) hysteresis loop with a negative (positive) sign.
*This work is supported by ARO (W911NF1810198), DOE (DE-SC0019064), and Alfred P. Sloan Research Fellowship.
–
Presenters
-
Yifan Zhao
- Pennsylvania State University
- Department of Physics, The Pennsylvania State University
- Department of Physics, Pennsylvania State University