Effective modulation of interfacial spin transport at CoFeB/Ta interface by ultrafast laser pulse

Abstract

In this study, we demonstrate the all-optical control of interfacial spin transport in CoFeB/Ta heterostructures using time-resolved magneto-optical Kerr effect measurements. Our results reveal a reduction in intrinsic Gilbert damping with increasing pump fluence, attributed to the laser-induced thermal modulation of spin diffusion length in Ta. The enhanced spin diffusion length at high pump fluences significantly regulates the spin current transmitted across the interface, leading to a modulation of interfacial spin transparency by up to 85%. These findings demonstrate the potential of ultrafast laser pulses as a noninvasive approach for controlling interfacial spin transport, offering new opportunities for spintronic device optimization.