An international team of researchers at the Universities of Göttingen, Bielefeld and Giessen, along with the Massachusetts Institute of Technology (MIT) in the USA, has now developed a new method that influences the electron’s thermopower in the tunnel junction by directly changing magnetisation. This way, they can control the conversion of heat into electrical energy. The results may contribute to the future development of novel, economical microprocessors.
Schematic diagram of how thermopower in the magnetic tunnel junction is switched via antiparallel (AP) or parallel (P) magnetisation.
DFG funds additional collaborative research to the tune of one million euros
Spin caloritronics is a new area of research: What happens when you heat up a magnet? When a material is heated, the temperature differential in the electrons generates an electrical voltage known as thermopower or the Seebeck effect. Electronic components made of magnetic materials – consisting of two magnetic layers separated by a thin oxide film only a few atomic layers thick – for example, are used as reading heads for hard drives. Current research focuses on the use of such magnetic tunnel junctions as nonvolatile memory elements in processors where data are preserved without an energy supply. An international team of researchers at the Universities of Göttingen, Bielefeld and Giessen, along with the Massachusetts Institute of Technology (MIT) in the USA, has now developed a new method that influences the electron’s thermopower in the tunnel junction by directly changing magnetisation. This way, they can control the conversion of heat into electrical energy. The results may contribute to the future development of novel, economical microprocessors and were published on Sunday, July 24, 2011 in the online issue of “Nature Materials“.
Elementary particles, many atomic nuclei and atoms with certain electron configurations have what is called spin – defined as the rotation of a body around its own axis. That enables alternative, spin-based methods of electronic data processing – called “spin electronics“. New synergies are created by merging the fields of spin electronics and the energy conversion of novel materials. A Japanese team of researchers recently showed that tunnel barriers enable thermal spin injection into the semiconductor silicon.
The team of researchers around the Göttingen physicist Professor Markus Münzenberg has now used laser power to heat up magnetic tunnel junctions and thereby discovered a novel effect: Thermopower was created during spin transport through the thin oxide layer (tunnel barrier) the heated up electrons traverse. They could raise or lower the thermopower by changing the magnetisation. In doing so, they influenced the thermopower of the whole magnetic tunnel junction. They predict that a change in thermopower of up to 1000 % is possible. This newly discovered effect involving the switching of thermopower in magnetic tunnel junctions was dubbed the magneto-Seebeck effect. “This has released the potential for us to locally control energy conversion in the tiniest of junctions and, in the future, for example, to channel back into the computer system the energy generated in microprocessors that previously went unutilised, or computer chips working with waste heat only” said Prof. Münzenberg, who leads a research group at the 1st Institute of Physics of Göttingen University. Since July 2011, the collaborative research of these working groups at the three German universities has been part of the priority programme titled “Spin Caloric Transport (SpinCat) – SPP 1538“, funded by the German Research Foundation (DFG) to the tune of over one million euros.Original publication:
Dr. Bernd Ebeling | Uni Göttingen
New test procedure for developing quick-charging lithium-ion batteries
07.12.2017 | Forschungszentrum Jülich
Plug & Play Light Solution for NOx measurement
01.12.2017 | Heraeus Noblelight GmbH
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications
Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...
Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.
The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...
Transistors based on carbon nanostructures: what sounds like a futuristic dream could be reality in just a few years' time. An international research team working with Empa has now succeeded in producing nanotransistors from graphene ribbons that are only a few atoms wide, as reported in the current issue of the trade journal "Nature Communications."
Graphene ribbons that are only a few atoms wide, so-called graphene nanoribbons, have special electrical properties that make them promising candidates for the...
08.12.2017 | Event News
07.12.2017 | Event News
05.12.2017 | Event News
08.12.2017 | Life Sciences
08.12.2017 | Information Technology
08.12.2017 | Information Technology