Fig. 4: Magnetic domain memory effect.
From: Ultrafast thermo-optical control of spins in a 2D van der Waals semiconductor
a–c Time-resolved MOKE images of the demagnetization of the domain structure at 1000 ps delay and for F = 1 mJ/cm2 with magnetic field μ0H = - 0.3 T (a), + 0.3 T (b) and 0 T (c), respectively. d Time-resolved MOKE images at μ0H = 0 T and F = 1 mJ/cm2 for different time delays. e Time-resolved MOKE images at μ0H = 0 T and at 1000 ps delay for different fluences F. f Schematic representation of the demagnetization process. Due to the finite penetration depth of the pump laser, the bottom layers stay intact during excitation and can imprint the domain structure pattern into the top layers spin via their stray field (white lines) as the magnetization recovers.
