Chirality reversal of resonant modes in GdFe ferrimagnets

Chirality of antiferromagnetic spin waves as an intrinsic degree of freedom has been attracting considerable attention due to its potential applications for magnonic devices. In this paper, atomistic-scale dynamics simulations were conducted to investigate the chirality of spin wave resonant modes in ferrimagnetic alloy GdxFe1-x (0 < x <1) under different proportion x and external magnetic fields near the angular momentum compensation point. Simulation results reveal that as the proportion of Gd increases, the resonance mode of spin waves undergoes two distinct handedness flipping at magnetization compensation point and angular momentum compensation point. When the proportion x deviates from the magnetization compensation point, a frequency degeneracy point emerges at a non-zero magnetic field, indicating that the chirality of spin waves can also be switched by an external magnetic field. A theoretical analysis is developed to explain the observed phenomena. These findings provide valuable insights into the control and manipulation of spin wave chirality in ferrimagnetic alloys, with potential implications for the development of spin-based devices and technologies.