Altermagnetism in MnTe: Origin, predicted manifestations, and routes to detwinning

MnTe has recently attracted attention as an altermagnetic candidate. Experimentally it has an altermagnetic order of ferromagnetic ab planes, stacked antiferromagnetically along c. We show that this magnetic order (by itself nontrivial, since the in-plane exchange in antiferromagnetic) opens intriguing possibility of manufacturing altermagnetically detwinned samples and generate observable magneto-optical response (which we calculate from first principles) as a signature of altermagnetism.