Group of Nanomagnetism and Magnetization Processes

We welcome Dr. Margarida Fernandes, from Universidade do Minho (Braga). She will be with us until the end of the year.

We welcome Fernando Meneses, PhD student from Universidad Nacional de Córdoba (Argentina). He will be with us until the end of the year.

ACS Nano, 2018

Magnetization Ratchet in Cylindrical Nanowires

Cristina Bran, Eider Berganza, Jose A. Fernandez-Roldan, Ester M. Palmero, Jessica Meier, Esther Calle, Miriam Jaafar, Michael Foerster, Lucia Aballe, Arantxa Fraile Rodriguez, Rafael P. del Real, Agustina Asenjo, Oksana Chubykalo-Fesenko, and Manuel Vazquez

DOI: 10.1021/acsnano.8b02153

The unidirectional motion of information carriers such as domain walls in magnetic nanostrips is a key feature for many future spintronic applications based on shift registers. This magnetic ratchet effect has so far been achieved in a limited number of complex nanomagnetic structures, for example, by lithographically engineered pinning sites. Here we report on a simple remagnetization ratchet originated in the asymmetric potential from the designed increasing lengths of magnetostatically coupled ferromagnetic segments in FeCo/Cu cylindrical nanowires. The magnetization reversal in neighboring segments propagates sequentially in steps starting from the shorter segments, irrespective of the applied field direction. This natural and efficient ratchet offers alternatives for the design of three-dimensional advanced storage and logic devices.