«Domain Wall Rebounds Driven by Competing Entropic and Spin Transfer Torques in Cylindrical Nanowires»
Elias Saugar, Jorge Marqués-Marchán, Sara Catalano, Agustina Asenjo, Michael Foerster, Miguel Angel Niño, Manuel Vazquez, Fèlix Casanova, Arantxa Fraile Rodríguez, Rafael P. Del Real, Oksana Chubykalo-Fesenko, Cristina Bran
Advanced Functional Materials,2026
DOI: 10.1002/adfm.202525734
Controlling domain walls in cylindrical geometries through energy-efficient spintronic methods is a key challenge for advancing future three dimmensional(3D) nanotechnologies.Here we used theX-ray Magnetic Circular Dichroism combined with Photoemission Electron Microscopy (XMCD-PEEM) technique to investigate domain wall dynamics in cylindrical magnetic nanowires under nanosecond current pulses. We found that small current densities (∼4×1011A/m2) effectively move domain walls and saturate the nanowire. Surprisingly, when the current density is further increased, the domain walls are not expelled from the nanowire. Instead, they rebound from the nanowire ends, with the rebound distance increasing as the pulse duration increases. Our modeling reveals that spin transfer torque dominates at lower currents, whereas at higher currents, it competes with a thermal gradient which pushes domain walls toward the nanowire center. These results underline the importance of thermal effects in cylindrical geometries and their implications for the design of robust spintronic devices.
DWs movement under high amplitude current pulses. XMCD-PEEM series of images taken after a pulse of 8×1011 A/m2 was applied repeatedly for (A) 10ns and (B) 20ns, respectively. Scale bar 1μm.
The authors acknowlodge the financial support from Spanish Ministry of Innovation and Science under projects PID2022-137567NB-C21 and RED2022-134649-T and the project Mag4TIC-CM(TEC-2024TEC-380)from the government of Madrid.
