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Ultrafast Spin Accumulations Drive Magnetization Reversal in Multilayers.
Harjinder Singh1, Alberto Anadón1, Junta Igarashi2
1IJL, CNRS, Université de Lorraine, Nancy, F-54000, France.
Physical Review Letters
|February 22, 2026
Summary
Ultrafast laser excitation in spintronic devices reveals how spin accumulation dynamics dictate magnetic switching. This work clarifies all-optical switching mechanisms for designing faster spintronic devices.
Area of Science:
- Spintronics
- Ultrafast magnetism
- Spin dynamics
Background:
- Controlling spin and heat transport on femtosecond timescales is crucial for high-speed spintronic devices.
- Understanding ultrafast magnetization reversal mechanisms is challenging due to difficulties in probing nonequilibrium spin dynamics.
Purpose of the Study:
- To demonstrate the use of magneto-optical experiments for probing spin accumulation dynamics.
- To elucidate the key mechanisms driving all-optical switching in magnetic multilayers.
Main Methods:
- Utilizing magneto-optical experiments to observe time-resolved spin accumulation.
- Analyzing ultrafast spin dynamics in magnetic multilayer stacks.
Main Results:
- Magneto-optical experiments can access the time evolution of spin accumulation after laser excitation.
- Reference layer magnetization dynamics significantly influence the free layer's final magnetic state.
- Demagnetization and remagnetization-driven spin accumulation are identified as the primary mechanism for all-optical switching.
Conclusions:
- Established principles for designing ultrafast spintronic devices through engineered spin currents.
- Disentangled magnetization and spin transport dynamics in multilayer systems.
- Highlighted the critical role of ultrafast spin dynamics in all-optical switching.
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