Berlin 2015 – scientific programme
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TT: Fachverband Tiefe Temperaturen
TT 58: Spincaloric Transport I (jointly with MA)
TT 58.8: Talk
Wednesday, March 18, 2015, 11:15–11:30, H 0110
Anisotropic magneto-thermopower in (Ga,Mn)As thin films — •Sibylle Meyer1,2, Matthias Althammer1, Wladimir Schoch3, Rudolf Gross1,2,4, and Sebastian T. B. Goennenwein1,4 — 1Walther-Meißner-Institut, Bayerische Akademie der Wissenschaften, Garching, Germany — 2Physik-Department, TU München, Garching, Germany — 3Institut für Quantenmaterie, Universität Ulm, Ulm, Germany — 4Nanosystems Initiative Munich, München, Germany
The resistance of ferromagnetic metals depends on the magnetization orientation. This is referred to as anisotropic magneto-resistance (AMR), and exploited in many applications. In close analogy, also the thermopower of magnetic metals depends on the magnetization orientation, i.e., the electrical field arising upon the application of a thermal gradient to the metal characteristically varies with the magnetization orientation (anisotropic magneto-thermopower AMTP). However, due to different symmetry restrictions, the evolution of AMR and AMTP with magnetization orientation is expected to be distinctly different.
To experimentally test this conjecture, we measured the AMTP in (Ga,Mn)As single crystals. Our data show that the AMTP effect can be adequately modeled only if the symmetry of the (Ga,Mn)As crystal is explicitly taken into account.
We quantitatively compare the AMTP with AMR data taken on the same (113)-oriented (Ga,Mn)As thin films and with corresponding model calculations.
Financial support by DFG via SPP 1538 is gratefully acknowledged.