Efficient domain-wall transport and pinning in magnetic nanowires and synthetic ferrimagnets

17 Feb 2017


TÍTULO: Efficient domain-wall transport and pinning in magnetic nanowires and synthetic ferrimagnets.

PONENTE: Dr. Henri Saarikoski, RIKEN Center for Emergent Matter Science, Wako, Japón.

LUGAR: CRAI Antonio de Ulloa, Aula TIC-2.

FECHA y HORA: Martes 21 de febrero de 2017, 12:00 hs.

ORGANIZADOR: Prof. Diego Frustaglia, Departamento de Física Aplicada II.   


Domain walls in ferromagnetic nanowires are potential building-blocks of future technologies such as racetrack memories, in which data encoded in the domain walls are transported using spin-polarised currents. However, the development of energy-efficient devices has been hampered by the high current densities needed to initiate domain wall motion as well as lack of efficient mechanism for fast and precise domain wall stopping and pinning.
We discuss here that a remarkable reduction in the critical current density can be achieved for in-plane magnetised coupled domain walls in CoFe/Ru/CoFe synthetic ferrimagnet tracks. Recent experiments have shown that the measured critical current density to set these walls in motion is almost an order of magnitude lower than in typical ferromagnetically coupled samples [1]. Theoretical modelling indicates that this is due to nonadiabatic driving of anisotropically coupled walls, a mechanism that can be used to design efficient domain-wall devices. Moreover, we propose that an array of locally-embedded Rashba interaction can be used as pinning centers for current-driven domain walls [2].

[1] S. Lepadatu, H. Saarikoski et al., arXiv:1604.07992 (2016).
[2] G. Tatara, H. Saarikoski, C. Mitsumata, Appl. Phys. Express 9 103002 (2016).