Experimental demonstration of 55-fs spin canting in photoexcited iron nanoarrays

摘要: As magnetic storage density approaches 1TB/in2, a grand challenge is looming as how to read/write such huge amount of data within reasonable time. The ultrafast optical manipulation magnetization offers solution, but little known about the intrinsic speed limit quantum spin switching. Here, we report that low-energy 50-fs laser pulses can induce canting in Fe nanoparticles 55 fs, breaking previous record by at least one order magnitude. Both linearly and circularly polarized light be used tilt spins. In our model, incident field first excites orbital angular momentum, through spin-orbit coupling, cants out-of-plane results distinctive diamond hysteresis loop. time decreases with momentum. This not limited also observed Fe/Pt Fe3O4 nanoparticles. Our demonstrate potential nanostructures viable medium for high densi...