Unraveling spin-orbit torque-induced multistate magnetization switching in Co/Gd ferrimagnetic multilayers for physically unclonable functions.

Ferrimagnetic materials driven by spin-orbit torque (SOT) exhibit a distinctive characteristic of multistate magnetization switching and enable versatile applications. However, the underlying mechanism governing multistate magnetization switching in ferrimagnetic materials remains unelucidated. Here, by studying SOT-induced magnetization switching in Co/Gd ferrimagnetic multilayers with perpendicular magnetic anisotropy (PMA), we demonstrate that the multistate magnetization switching behavior is observed not only in [Co/Gd] but also in [Co/Gd]/CoFeB stacks and size-shrinking dot devices.

Orbitronics: light-induced orbital currents in Ni studied by terahertz emission experiments.

Orbitronics is based on the use of orbital currents as information carriers. Orbital currents can be generated from the conversion of charge or spin currents, and inversely, they could be converted back to charge or spin currents. Here we demonstrate that orbital currents can also be generated by femtosecond light pulses on Ni.

An integrated ultra-high vacuum cluster for atomic-scale deposition, interface regulation, and characterization of spintronic multilayers.

The study of interface spin effects in spintronic multilayer films requires distinguishing the effects generated by different interfaces. However, testing in atmospheric conditions requires a capping layer to protect the films, which introduces new interfaces and limits the study of interface spin-dependent effects. To address this challenge, we have developed an integrated ultra-high vacuum cluster system that includes magnetron sputtering equipment, ion irradiation equipment, and time-resolved magneto-optical Kerr effect (TR-MOKE) equipment.