Theory of giant thermal magnetogalvanic effects in magnetic tunnel junctions

• Applicant: Professor Dr. Christian Heiliger
• Subject Area: Theoretical Condensed Matter Physics
• Term: from 2011 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 197678537

Magnetic tunnel junctions with MgO as a barrier are promising candidates for spin-caloric applications. The MgO barrier acts as a symmetry filter which leads to a high spin polarized current when CoFe magnetic layers are used. Such junctions show a huge difference in the transport properties of both spin channels. Consequently, one can expect also huge spin-caloric effects like magnetothermoelectric power. A drawback of CoFe alloys is the short spin diffusion length which makes this system less suitable for the spin-Seebeck effect. This insufficiency can be overcome by using halfmetallic leads. In particular, we will focus on the Co2FeAl Heusler compound. In this project we perform ab intio calculations of the spin-Seebeck (or spin-dependent Seebeck) effect and the magento-thermoelectric power. Further we will develop a method to account for electron-magnon coupling to calculate transport properties and the spin-transfer torque as a function of temperature.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1538: Spin Caloric Transport (SpinCaT)