High domain wall velocity at zero magnetic field induced by low current densities in spin-valve nanostripes

Stefania Pizzini (1) , Vojtech Uhlir (1) , Jan Vogel (1) , Nicolas Rougemaille (1) , Sana Laribi (2) , Vincent Cros (2) , Erika Jimenez (3) , Julio Camarero (3) , Carsten Tieg (4) , Edgar Bonet (5) , Marlio Bonfim (6) , Richard Mattana (2) , Cyrile Deranlot (2) , Frédéric Petroff (2) , Christian Ulysse (7) , Giancarlo Faini (7) , Albert Fert (2)

1 NEEL - MNM - Micro et NanoMagnétisme
2 Laboratoire Albert Fert (ex-UMPhy Unité mixte de physique CNRS/Thales)
3 FMC - Departamento de Fisica de la Materia Condensada [Madrid]
4 ESRF - European Synchrotron Radiation Facility
5 NEEL - QuantECA - Circuits électroniques quantiques Alpes
6 Departamento de Engenharia Elétrica
7 LPN - Laboratoire de photonique et de nanostructures

Current-induced magnetic domain wall motion at zero magnetic field is observed in the permalloy layer of a spin-valve-based nanostripe using photoemission electron microscopy. The domain wall movement is hampered by pinning sites, but in between them high domain wall velocities (exceeding 150 m/s) are obtained for current densities well below $10^{12} \unit{A/m^2}$, suggesting that these trilayer systems are promising for applications in domain wall devices in case of well controlled pinning positions. Vertical spin currents in these structures provide a potential explanation for the increase in domain wall velocity at low current densities.

Mots clés: spin transfer torque; domain wall; spin-valve; PEEM

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Stefania Pizzini, Vojtech Uhlir, Jan Vogel, Nicolas Rougemaille, Sana Laribi, et al.. High domain wall velocity at zero magnetic field induced by low current densities in spin-valve nanostripes. Japanese Journal of Applied Physics, part 2 : Letters, 2009, 2, pp.023003. ⟨10.1143/APEX.2.023003⟩. ⟨hal-00332055v2⟩