Chiral magnons in the metallic altermagnet CrSb

CrSb has been identified as a prominent candidate for observing altermagnetic (AM) chiral-split magnon spectra. AMs are novel spintronic platforms due to their strong time reversal symmetry-breaking responses akin to ferromagnets and fully compensated magnetization typical of collinear antiferromagnets (AFMs). CrSb orders ferromagnetically (Tc=705 K) with the [001] planes coupled antiferromagnetically along the easy c-axis. ARPES measurements have revealed a spin-split band structure reaching up to 1eV, but evidence for the predicted spin-split chiral magnon spectra is lacking. Inelastic neutron scattering measurements resolved a gapped magnon dispersion (~10 meV) with a bandwidth of ~60meV. We propose a momentum and polarization-resolved RIXS experiment at the Cr L2,3 edge (~580 eV) to reveal the time-reversal symmetry-breaking nature of the low energy magnetic excitations in CrSb.