Dresden 2011 – scientific programme

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MA: Fachverband Magnetismus

MA 62: Magnetic Imaging

MA 62.2: Talk

Friday, March 18, 2011, 11:00–11:15, HSZ 04

Quantification of spin torque and Joule heating using SP-STM — •Stefan Krause, Gabriela Herzog, Anika Schlenhoff, Andreas Sonntag, and Roland Wiesendanger — Institute of Applied Physics, University of Hamburg

Spin-polarized scanning tunneling microscopy (SP-STM) is a powerful tool not only to image but also to manipulate magnetic nanostructures at ultimate lateral resolution. Using a high spin-polarized current originating from a magnetic tip the thermal magnetization switching behavior of an individual Fe/W(110) monolayer nanoisland with uniaxial anisotropy is influenced: Whereas Joule heating increases the switching frequency, the spin torque lifts the degeneracy of the two magnetic state lifetimes, forcing the island to favor one magnetic orientation.[1,2]

In general, the microscopic details of spin torque and Joule heating are still to be discovered. The capability of SP-STM to inject a high tunnel current into an individual nanoisland and simultaneously monitor its magnetic state allows for a direct quantification of spin torque and Joule heating from the observed switching behavior. The results are discussed in terms of current-dependent state lifetimes and interpreted as the modification of the switching energy barrier due to spin torque and an increased temperature of the nanoisland due to Joule heating.

[1] S. Krause et al., Science 317, 1537 (2007).

[2] G. Herzog, S. Krause and R. Wiesendanger, Appl. Phys. Lett. 96, 102505 (2010).