Regensburg 2019 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 6: Surface magnetism and magnetic coupling phenomena (joint session MA/O/TT)

TT 6.1: Talk

Monday, April 1, 2019, 09:30–09:45, H53

Magneto-Seebeck Tunneling on the Atomic Scale — Cody Friesen, •Hermann Osterhage, Johannes Friedlein, Anika Schlenhoff, Roland Wiesendanger, and Stefan Krause — Department of Physics, University of Hamburg, Germany

The tunneling of spin-polarized electrons in a magnetic tunnel junction driven by a temperature gradient is a fundamental process for the thermal control of electron spin transport. As we have shown recently, scanning Seebeck tunneling microscopy is a technique that enables spin-averaged thermopower measurements in a metal-vacuum-metal tunnel junction with atomic-scale lateral resolution [1]. Using a magnetic tip and sample allows for the experimental investigation of the details of the magneto-Seebeck tunneling, with vacuum serving as the tunneling barrier. Heating the tip with a laser and measuring the thermopower of the junction while scanning across the spin texture of the sample leads to spin-resolved Seebeck coefficients that can be determined and mapped with atomic-scale lateral resolution [2].

The experiments on Fe/W(110) and Fe/Ir(111) will be presented and discussed in terms of spin-averaged, magneto-Seebeck and anisotropic magneto-Seebeck thermopower in an ideal single atom tunnel junction. Based on the experimental findings we propose a spin detector for spintronics applications that is solely driven by waste heat, utilizing magneto-Seebeck tunneling to convert spin information into a voltage that can be used for further data processing.

[1] C. Friesen et al., J. Phys. D: Appl. Phys. 51, 324001 (2018).

[2] C. Friesen et al., Science (accepted).