Fig. 1: Demagnetization and optically induced domain formation in CrI3 (sample 1).
From: All-optical control of spin in a 2D van der Waals magnet
a Schematic of the experimental setup and optical image of a ~40 nm bulk CrI3 flake on Si/SiO2 (sample 1). Magnetic domains are imaged in a wide-field Kerr microscope (WFKM), by detecting polarization changes of the reflected light due to the polar Kerr effect, following excitation with laser pulses. b Formation of domain structure after consecutive single laser pulses (N = 1, 2, 3) with 1.88 eV photon energy, linear polarization, ~30 fs pulse duration and fluence F = 3.4 mJ/cm2. The blue (red) color scale represents the Kerr signal corresponding to the magnetization orientation M↑(M↓). The measurements were performed at 20 K. The scale bar has 5 μm in length. c Simulated domain structures after the application of consecutive laser pulses using atomistic simulation methods. d Time evolution of the spatially averaged out-of-plane magnetization following application of the N = 1 laser pulse; (Inset) Electron Te and phonon Tp temperatures calculated from the two-temperature model. e Evolution of magnetic domains following the application of an ultrafast laser pulse at different time steps. The scale bars in c and e have 100 nm lengths.
