Most of our research uses the spin or the magnetic moment of the solid state (quasi-) particles to store or process information, which is part of spinelectronics. We investigate spin polarized transport in complex devices and we try to find and characterize new functional materials.
In the center of many of our research activities is the magnetic tunnel junction. Magnetic tunnel junctions can be the base for magnetic sensors, magnetic memory and reconfigurable logics. Here, electrodes with perpendicular magnetic anisotropy are promising materials for future devices.
If one electrode is replaced by a superconducting Aluminum layer, the so called spin polarization of the other electrode can be measured. This technique is perfectly suited to complement the TMR measurement and inelastic electron tunneling spectroscopy of, e.g., Heusler compounds or MgO based structures.
The Heusler compounds are a particularly interesting materials class for electrode materials. Heusler compounds can show half metallic or superconducting behavior, even topological insulators have been predicted. If we functionalize not the electrode but the tunnel barrier of a magnetic tunnel junction, we can also observe memristive behavior in ultra-thin tunnel barriers. This is funded by an NRW independent researcher grant.
Besides nano-scale multilayer systems, we plan further investigations of nanostructures. Right now, these are single molecule magnets prepared by Prof. T. Glaser in Bielefeld. This research is part of the DFG research unit Nanomagnets.
The newest research direction explores new physics in spin dependent devices exposed to a temperature gradient, which is called spin caloritronics. In collaboration with M. Münzenberg in Göttingen, we look into the magneto Seebeck effect in magnetic tunnel junctions. This is done in the framework of the DFG priority program SpinCaT.
Please send emails to Andy Thomas (andy.thomas@uni-bielefeld.de).
For my research profile please visit research id:
M. Weiler, M. Althammer, F. D. Czeschka, H. Huebl, M. S. Wagner, M. Opel, I.-M. Imort, G. Reiss, A. Thomas, R. Gross, and S. T. B. Goennenwein: Local charge and spin currents in magnetothermal landscapes, Phys. Rev. Lett., accepted for publication
P. Krzysteczko, J. Münchenberger, M. Schäfers, G. Reiss, A. Thomas: The memristive magnetic tunnel junction as a nanoscopic synapse-neuron-system, Adv. Materials 24 (2012) 762
M. Walter, J. Walowski, V. Zbarsky, M. Münzenberg, M. Schäfers, D. Ebke, G. Reiss, A. Thomas, P. Peretzki, M. Seibt, J.S. Moodera, M. Czerner, M. Bachmann, C. Heiliger: 'Seebeck Effect in Magnetic Tunnel Junctions', Nature Materials 10 (2011) 742
