When "frustrated" by their arrangement, magnetic atoms surrender their individuality, stop competing with their neighbors and then practice a group version of spin control—acting collectively to achieve local magnetic order—according to scientists from the Commerce Departments National Institute of Standards and Technology, Johns Hopkins University and Rutgers University writing in the Aug. 22, 2002, issue of the journal Nature.
Chill! Atoms in zincochromite, a "geometrically frustrated magnet," resolve their frustration through group spin control. Neighboring tetraheda (solids with four triangular faces) contribute a side each to create hexagonal (six-sided) spin clusters. A hexagon bunches the spins of magnetic atoms-one at each corner-into a single "spin director" (arrows). The composite behavior achieves local magnetic order.
The unexpected composite behavior detected in experiments done at the NIST Center for Neutron Research (NCNR) accounts for the range of surprising—and, heretofore, unexplainable—properties of so-called geometrically frustrated magnets, the subject of intensifying research efforts that may lead to new types of matter. The finding also may shed light on natural clustering processes including the assembly of quarks and other minuscule components into atoms, the folding of proteins and the clumping of stars in galaxies, the scientists say.
These and other important phenomena—including high-temperature superconductivity—suggest that there are "higher-order organizing principles that are intrinsic to nature," explains lead author Seung-Hun Lee, NCNR staff physicist.
Mark Bello | EurekAlert!
Comet or asteroid? Hubble discovers that a unique object is a binary
21.09.2017 | NASA/Goddard Space Flight Center
First users at European XFEL
21.09.2017 | European XFEL GmbH
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.
MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...
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21.09.2017 | Physics and Astronomy
21.09.2017 | Life Sciences
21.09.2017 | Health and Medicine