WASHINGTON - In a new research, a team of scientists has for the first time observed magnetic monopoles and how they emerge in a real material.
The research was done by scientists from the Helmholtz-Zentrum Berlin fur Materialien und Energie, Germany, in cooperation with colleagues from Dresden, St. Andrews, La Plata and Oxford.
Magnetic monopoles are hypothetical particles proposed by physicists that carry a single magnetic pole, either a magnetic North pole or South pole.
In the material world, this is quite exceptional because magnetic particles are usually observed as dipoles, north and south combined.
However, there are several theories that predict the existence of monopoles.
Among others, in 1931, the physicist Paul Dirac was led by his calculations to the conclusion that magnetic monopoles can exist at the end of tubes - called Dirac strings - that carry magnetic field.
Until now, they have remained undetected.
Jonathan Morris, Alan Tennant and colleagues (HZB) undertook a neutron scattering experiment at the Berlin research reactor. The material under investigation was a single crystal of Dysprosium Titanate.
This material crystallises in a quite remarkable geometry, the so-called pyrochlore-lattice.
With the help of neutron scattering, Morris and Tennant showed that the magnetic moments inside the material had reorganised into so-called “Spin-Spaghetti”.
This name comes from the ordering of the dipoles themselves, such that a network of contorted tubes (Strings) develops, through which magnetic flux is transported.
These can be made visible by their interaction with the neutrons which themselves carry a magnetic moment. Thus, the neutrons scatter as a reciprocal representation of the Strings.
During the neutron scattering measurements, a magnetic field was applied to the crystal by the researchers. With this field, they could influence the symmetry and orientation of the strings.
Thereby, it was possible to reduce the density of the string networks and promote the monopole dissociation.
As a result, at temperatures from 0.6 to 2 Kelvin, the strings are visible and have magnetic monopoles at their ends.
The signature of a gas made up by these monopoles has also been observed in heat capacity measured by Bastian Klemke (HZB).
Providing further confirmation of the existence of monopoles and showing that they interact in the same way as electric charges.
In this work, the researchers, for the first time, attest that monopoles exist as emergent states of matter, that is, they emerge from special arrangements of dipoles and are completely different from the constituents of the material. (ANI)
Related News
Physicists observe magnetism in gas for the first timeOctober 3rd, 2009 TORONTO - An international team of physicists has for the first time observed magnetic behaviour in an atomic gas, addressing a decades-old debate as to whether it is possible for a gas or liquid to become ferromagnetic and exhibit magnetic properties. "Magnets are all around us - holding postcards on the refrigerator, pointing to magnetic north on a compass, and in speakers and headphones - yet some mysteries remain," said Joseph H.
New graphite-based nano-material may herald next generation of electronic devicesSeptember 3rd, 2009 WASHINGTON - An international team of researchers has designed a new graphite-based, magnetic nano-material that acts as a semiconductor and could help material scientists create the next generation of electronic devices like microchips. The nano-material was designed by a team of researchers from Virginia Commonwealth University (VCU); Peking University in Beijing, China; the Chinese Academy of Science in Shanghai, China; and Tohoku University in Sedai, Japan.
Diving at dawn and dusk help tuna to navigate with internal compassAugust 24th, 2009 LONDON - A new study has suggested that tuna dive fast and deep twice a day, namely around dawn and dusk, because they use an internal compass to navigate. It has long been known that tuna dive around dawn and dusk but no one has been quite sure why.
'Invisibility cloaks' come closer to realityJuly 8th, 2009 WASHINGTON - A team of researchers at the Universitat Autonoma de Barcelona (UAB) have come up with a device called a dc metamaterial, which makes objects invisible under certain light. The device does so, according to the researchers, under very low frequency electromagnetic waves by making the inside of the magnetic field zero, but not altering the exterior field.
Cosmic 'whips' may be detected with gravitational wavesJuly 6th, 2009 LONDON - A new research has determined that cosmic 'whips', which are topological defects in space-time larger than the observable universe, can be detected with the help of gravitational waves. Many theories predict the existence of cosmic strings.
Mixing in Earth's outer core causes geomagnetic dipole to collapseJuly 4th, 2009 WASHINGTON - Scientists have performed numerical calculations that show how convective mixing flows in the Earth's liquid outer core can cause the geomagnetic dipole to collapse. For the past 160 years, the Earth's magnetic dipole has been weakening at a rate of nearly six percent per century.
Homing pigeons' inbuilt 'satnav' that uses Earth's magnetic field helps them return homeJune 24th, 2009 LONDON - Homing pigeons have fascinated humans for many years through their uncanny ability to find their way home from thousands of miles away. Now, researchers claim to have found the reason behind it.
Astronomers obtain first detection of magnetic field on bright star VegaJune 24th, 2009 PARIS - Astronomers, using the NARVAL spectropolarimeter of the Bernard-Lyot telescope in France, have obtained the first detection of a magnetic field on the bright star Vega. According to an article in the journal Astronomy and Astrophysics, astronomers clearly observe the magnetically-induced effect in the spectrum of Vega, thereby showing that the star possesses a magnetic field, something unknown so far.
Earth's magnetic poles may wander due to ocean currentsJune 20th, 2009 LONDON - A controversial new hypothesis has proposed that oceans' currents are responsible for the slow wandering of the Earth's magnetic poles. According to a report in New Scientist, the theory has been put forward by physicist Gregory Ryskin of Northwestern University in the US.
Color-changing fabricated material may pave way for rewritable color display unitsJune 17th, 2009 WASHINGTON - Scientists have created a new fabricated material that changes color instantly in response to external magnetic field, which could pave the way for manufacturing rewritable color display units and environmentally friendly color paints. A research team, led by a chemist at the University of California, Riverside, created the material.
Enormous eruption reveals dead star in deep spaceJune 17th, 2009 PARIS - Astronomers, using ESA's (European Space Agency's) XMM-Newton and Integral space observatories, have observed an enormous eruption, which after careful analysis, has revealed a dead star belonging to a rare group: the magnetars. X-Rays from the giant outburst arrived on Earth on August 22, 2008, and triggered an automatic sensor on the NASA-led, international Swift satellite.
Miniscule magnets in ant antennae act as internal GPSMay 22nd, 2009 WASHINGTON - A new research has led to the discovery of miniscule magnets in ant antennae, which act as an internal GPS (Global positioning system), making these insects aware as to where they are going. According to a report in Discovery News, while human global positioning systems rely upon receivers that pick up information from a network of satellites, the probable ant system weighs next to nothing, requires little energy to operate and appears to be mostly built out of dirt.
Eco friendly magnetic fridges and AC's come step closer to realityMay 16th, 2009 WASHINGTON - A new research has brought environmentally friendly 'magnetic' refrigerators and air conditioning systems a closer to reality. Magnetic refrigeration technology could provide a 'green' alternative to traditional energy-guzzling gas-compression fridges and air conditioners.
Scientists reveal secrets of graphene's extraordinary propertiesMay 15th, 2009 WASHINGTON - In a new analysis, scientists have directly measured the unusual energy spectrum of graphene, which adds new detail to help explain the extraordinary properties of the material. The analysis was done by researchers from the Georgia Institute of Technology and the National Institute of Standards and Technology (NIST).
"Supergiant" asteroid shut down magnetic field of MarsMay 12th, 2009 WASHINGTON - In a new research, scientists suggest that a "supergiant" asteroid several times larger than the one that likely killed the dinosaurs struck Mars with such force that it shut down the planet's magnetic field. Based on the number of large craters present, scientists think very early Mars suffered 15 or so giant impacts within a span of about a hundred million years.
Loading ...