Observation of anomalous Hall effect in Mn3GaN p-wave magnet

Unconventional antiferromagnets with spin splitting have garnered significant interest due to their unique characteristics. Recently, a new class of p-wave magnets has been predicted to induce significant spin-splitting in electronic bands within momentum space. However, the protection of time-reversal symmetry typically suppresses the observation of anomalous Hall effect (AHE), thereby limiting its potential applications. In this study, a giant anomalous Hall conductivity (AHC) exceeding 180  S cm⁻¹ is observed in Mn ₃ GaN. Through electronic transport measurements, we demonstrate that the AHE is driven by the broken spatial inversion symmetry, characteristic of p-wave magnets, with upon further breaking of time-reversal symmetry via weak magnetization. First-principles calculations show that the observed AHE is linked to slight spin canting that break time-reversal symmetry. The band splitting in p-wave magnets further enhances the magnitude of the AHC variation. Our findings pave the way for the development of unconventional p-wave magnets in antiferromagnetic physics and spintronics.