Regensburg 2007 – scientific programme
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MA: Fachverband Magnetismus
MA 27: Micro- and Nanostructured Magnetic Materials II
MA 27.11: Talk
Thursday, March 29, 2007, 17:45–18:00, H22
Current induced magnetization switching — a possible application for SP-STM? — •Stefan Krause1, Luis Berbil-Bautista1,2, Gabriela Herzog1, Matthias Bode1, and Roland Wiesendanger1 — 1Institute of Applied Physics, University of Hamburg, Germany — 2Department of Physics, University of California at Berkeley, USA
In present MRAM devices magnetic nanostructures are switched by magnetic fields. Due to their non-local character, however, cross-talk between adjacent nanomagnets may occur. An elegant method to circumvent this problem is magnetization switching by spin-polarized currents, as observed in GMR [1] as well as in TMR [2] devices. However, the layered structures of these devices do not provide any insight to the details of the spatial distribution of the switching processes.
Spin-polarized scanning tunneling microscopy (SP-STM) is a well-established tool to reveal the magnetic structure of surfaces with spatial resolution down to the atomic scale. Besides, SP-STM takes advantage of a perfect TMR junction consisting of a vacuum barrier separating two magnetic electrodes, which are represented by the foremost tip atom and the sample. This configuration excludes undesirable influences of layer intermixing and lattice imperfections which may play an important role in MBE-grown TMR junctions. We will report on our SP-STM experiments to switch the magnetization by the injection of a spin-polarized current.
[1] J. A. Katine et al., Phys. Rev. Lett. 84, 3149 (2000).
[2] Y. Liu et al., Appl. Phys. Lett. 82, 2871 (2003).