Spin wave dynamics excited by a focused laser pulse in antiferromagnet CrSBr

The authors theoretically study here laser-induced magnetization dynamics in van der Waals antiferromagnetic CrSBr films by analyzing the spatiotemporal evolution of the magnetization from thermal and nonthermal mechanisms. For the thermal mechanism, the presence and the symmetry of spatial patterns strongly rely on the nonuniformity of shear stress and the strength of the magnetic field. For the nonthermal one, an isotropic spin-wave propagation appears at zero field and becomes anisotropic at finite magnetic field.