Single-shot laser-pulse-induced magnetization reversal in CoFeB/MgO-based magnetic tunnel junctions

We demonstrate single-shot laser-pulse-induced magnetization reversal in rare-earth-free CoFeB/MgO magnetic tunnel junctions (MTJs), a material system widely adopted in spin-transfer torque magnetic random-access memory. By tuning the Ru capping layer thickness, we modify the laser energy absorption profile and observe magnetization reversal from the parallel to antiparallel state, with switching observed for tRu ≥ 2.0 nm. Furthermore, we detect magnetization reversal in a micro-scale MTJ device via the tunnel magnetoresistance effect. Our findings suggest that ultrafast spin transport, dipolar interactions, or a combination of both may contribute to the switching process, although the precise mechanism remains to be clarified. This work represents a significant step toward integrating ultrafast optical control with MTJ technology.