Photo-induced magneto-optical Kerr effect in europium sulfide EuS

The photoinduced magnetization in europium sulfide EuS was studied by the magneto-optical Kerr effect. It is experimentally established that when a sample is exposed to light with a photon energy greater than the band gap, photoinduced magnetization arises, associated with the formation of magnetic polarons with a large magnetic moment of about 3000 $\mu$B. The polarons are excited in a narrow temperature range of 12–18 K and form a superparamagnetic ensemble with an average polaron lifetime of 13 $\mu$s. An experimental setup for measuring photoinduced magnetization with the optical pump-and-probe method is described.