Anomalous Hall Effect In Mnas: Intrinsic Contribution Due To Berry Curvature

We present an experimental and theoretical study of the anomalous Hall effect (AHE) in MnAs epilayers grown over GaAs, with the aim to identify the intrinsic contribution to the AHE, which can be accurately evaluated using ab initio electronic structure calculations. Our magnetotransport measurements show a quadratic behavior of the Hall resistivity with longitudinal resistivity, characteristic of scattering-independent processes, thus enabling the comparison with our ab initio calculations. The calculated Berry phase contribution to the AHE is in quantitative agreement with the measured AHE in these epilayers. Moreover, the predicted anisotropic dependence of the experimental AHE on the magnetization is well reproduced.