Sublattice-Selective Inverse Faraday Effect in Ferrimagnetic Rare-Earth Iron Garnet

We performed time-resolved pump–probe measurements using rare-earth iron garnet Gd_3/2Yb_1/2BiFe₅O₁₂ as a two-sublattice ferrimagnet. We measured the initial phases of the magnetic resonance modes below and above the magnetization compensation temperature to clarify the sublattice selectivity of the inverse Faraday effect in ferrimagnets. A comparison of the time evolution of magnetization estimated using the equations of motion revealed that the inverse Faraday effect occurring in ferrimagnetic materials has sublattice selectivity. This is in striking contrast to antiferromagnets, in which the inverse Faraday effect acts on each sublattice identically. The initial phase analysis can be applied to other ferrimagnets with compensation temperatures.