Heusler alloy NiMnSb could prove valuable as a new material for digital information processing and storage
In today’s world of ever-increasing digital information storage and computation, the next information storage revolution seeks to exploit a novel effect arising from the relativistic physics of Einstein which allows to make a new type of magnet behave like cats.
Similar to the ability of a cat to flip itself in the air by twisting different parts of its body in different directions and land on its feet, these magnets can flip themselves through the internal motion of their own electrons.
"In these new magnetic materials, a current running through the magnet can turn around the direction of the magnetization depending on the direction of the current," explained Professor Jairo Sinova of the Institute of Physics at Johannes Gutenberg University Mainz (JGU).
"This novel phenomenon in physics, dubbed spin-orbit torques, links the spin-degree of freedom of magnets which gives rise to the magnetization to the charge degree of freedom that allows for current-charge motion inside the material.
This novel effect has been pioneered, among others, by recent predictions by the Sinova group in Mainz together with theoretical and experimental collaborators. It occurs in magnetic materials that have broken-inversion symmetry.
The researchers first observed spin-orbit torques in the artificial bulk diluted magnetic semiconductor GaMnAs. GaMnAs is the diluted counterpart of crystalline zincblende structures of Silicon and Gallium arsenide, which are the pillars of modern electronics. However, in GaMnAs, spin-orbit torques were demonstrated only at very low temperatures.
In collaboration with an international team of researchers from Prague, Cambridge, Würzburg, Jülich, and Nottingham, Professor Jairo Sinova and his Ph.D. students Jacob Gayles and Libor Šmejkal now have published their findings, which could pave the way for using spin-orbit torques in technological applications.
Thanks to the synergetic teamwork of theorists and experimentalists, the researchers were able to predict and demonstrate the effect of spin-orbit torques in NiMnSb crystal at room temperature. NiMnSb was chosen according to the systematic analysis of the symmetry the crystal point groups in conjunction with microscopic first principles calculations of the effect.
All electrical ferromagnetic resonance measurements were then used to detect the room-temperature spin-orbit torques in NiMnSb microbars. Being able to use single magnet manipulation at room temperature represents an important step towards improved magnetic random access memory architectures for technical applications that are all fully electrical, highly scalable, and require low power.
C. Ciccarelli, L. Anderson et al.
Room-temperature spin-orbit torque in NiMnSb
Nature Physics, 16 May 2016
Flipping NiMnSb magnet
ill.:/©: Inspire Group, JGU
Professor Dr. Jairo Sinova
Spintronics and Nanoelectronics Theory Group
Institute of Physics
Johannes Gutenberg University Mainz
55099 Mainz, GERMANY
phone +49 6131 39-23646
fax +49 6131 39-23474
http://www.nature.com/nphys/journal/vaop/ncurrent/full/nphys3772.html - Publication ;
http://www.uni-mainz.de/presse/59190.php – press release "Jairo Sinova receives ERC funding to develop new spintronic concepts" (22 January 2014)
Petra Giegerich | idw - Informationsdienst Wissenschaft
New creepy, crawly search and rescue robot developed at Ben-Gurion U
19.07.2018 | American Associates, Ben-Gurion University of the Negev
The role of Sodium for the Enhancement of Solar Cells
17.07.2018 | Max-Planck-Institut für Eisenforschung GmbH
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
19.07.2018 | Materials Sciences
19.07.2018 | Earth Sciences
19.07.2018 | Life Sciences