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 (STT-MRAM).

By tuning the Ru capping layer thickness, we modify the laser energy absorption profile and observe magnetization reversal from the parallel (P) to antiparallel (AP) state, with switching observed for $t_\text{Ru} \geq 2.0\,$ nm.

Furthermore, we detect magnetization reversal in a micro-scale MTJ device via the tunnel magnetoresistance (TMR) 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.