Photocontrol of Magnetic Domain Structure in Manganite Thin Films by Linearly Polarized Femtosecond Laser Pulse.

Ultrafast spin control with low energy consumption is a current hotspot in spintronics. Here, we report a nonthermally controlled manipulation of the magnetic domain wall (DW) pattern in La0.67Sr0.33MnO3 films using linearly polarized femtosecond (LPF) laser pulse illumination: under illumination, DWs are driven to move perpendicular to the laser polarization direction. Furthermore, the volumetric energy density threshold required for the single laser pulse to drive the DW motion in the LSMO was determined to be as low as 57 J/cm3, over an order of magnitude lower than the reported values for electric currents via spin-transfer or spin-orbit torque. Ultrafast spectroscopy measurements, combined with the polarization-dependent observations, indicate that LPF-driven excitation of the DW translation mode (with polarization selectivity) is the underlying mechanism responsible for the optical DW alignment. Leveraging this nonthermal photomagnetic effect, an all-optical control of the DW anisotropic resistance effect was implemented. This optical alignment of the magnetic DW induced by LPF laser offers a perspective for understanding the photomagnetic effects, providing potential for developing an optospintronic device with high speed and low energy cost.