Exploring the Magnetic Ground State of Epitaxial MnTe Films

We observe a previously unreported sign reversal in the anomalous Hall effect of ultra-high quality MnTe films grown on (111)A-oriented InP via molecular beam epitaxy. MnTe is a leading candidate for altermagnetism, a newly identified class of antiferromagnets with potential enormous advantages as the basis for spintronic devices. As the altermagnetic state is extremely sensitive to small perturbations in the spin structure, we seek to perform neutron diffraction above and below the sign reversal, and in a saturated magnetic state, to determine the temperature-dependent evolution of the magnetic structure.