Momentum Microscopy Study on Strained Thin Films of Altermagnetic MnTe

Altermagnets are a novel type of magnet characterized by alternating spin splitting in the band structure despite compensated, collinear magnetic moments in real space. When there are rotational symmetries that enable broken time reversal symmetry, these materials can exhibit spontaneous magneto-transport phenomena arising from electronic symmetry, including the anomalous Hall effect (AHE). To date, the ability to tune the AHE in altermagnets on demand is lacking. Recently, it was discovered that the AHE can be tuned by an external magnetic field when the altermagnetic manganese telluride (MnTe) is spontaneously strained by epitaxial growth on GaAs substrates. Here we use momentum microscopy to study strain-dependent changes to the band structure and compare our results to DFT calculations for different possible point groups of MnTe.