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Category: particle physics – Page 517

A ‘breath of nothing’ provides a new perspective on superconductivity

Zero electrical resistance at room temperature? A material with this property, i.e. a room temperature superconductor, could revolutionize power distribution. But so far, the origin of superconductivity at high temperature is only incompletely understood. Scientists from Universität Hamburg and the Cluster of Excellence “CUI: Advanced Imaging of Matter” have succeeded in observing strong evidence of superfluidity in a central model system, a two-dimensional gas cloud for the first time. The scientists report on their experiments in the journal Science, which allow to investigate key issues of high-temperature superconductivity in a very well-controlled model system.

There are things that aren’t supposed to happen. For example, water cannot flow from one glass to another through the glass wall. Surprisingly, allows this, provided the barrier between the two liquids is thin enough. Due to the quantum mechanical tunneling effect, particles can penetrate the barrier, even if the barrier is higher than the level of the liquids. Even more remarkably, this current can even flow when the level on both sides is the same or the current must flow slightly uphill. For this, however, the fluids on both sides must be superfluids, i.e. they must be able to flow around obstacles without friction.

This striking phenomenon was predicted by Brian Josephson during his doctoral thesis, and it is of such fundamental importance that he was awarded the Nobel Prize for it. The current is driven only by the wave nature of the superfluids and can, among other things, ensure that the begins to oscillate back and forth between the two sides—a phenomenon known as Josephson oscillations.

New insights into van der Waals materials found

Layered van der Waals materials are of high interest for electronic and photonic applications, according to researchers at Penn State and SLAC National Accelerator Laboratory, in California, who provide new insights into the interactions of layered materials with laser and electron beams.

Two-dimensional van der Waals materials are composed of strongly bonded layers of molecules with weak bonding between the layers.

The researchers used a combination of ultrafast pulses of laser light that excite the atoms in a material lattice of gallium telluride, followed by exposing the lattice to an ultrafast pulse of an . This shows the lattice vibrations in real time using and could lead to a better understanding of these materials.

Breakthrough in dark matter mystery as neutral hydrogen from other galaxies detected for first time

In a development that could finally shed light on dark matter, an international team of scientists have detected neutral hydrogen atoms, from a galaxy other than our own, for the very first time.

The finding came thanks to the enormous Five-hundred-meter Aperture Spherical Radio Telescope (FAST), which sits in a hilly, green natural basin in southwest China’s Guizhou Province.

The researchers detected the hydrogen coming from three extragalactic galaxies with only five minutes of exposure, a feat that demonstrates the exceptional sensitivity of the telescope. It is the first time neutral hydrogen from outside the Milky Way has been detected.

Pentadiamond: Scientists Devise a Way to Build a Harder Diamond

Scientists at the University of Tsukuba use computer calculations to propose a new way to rearrange the carbon atoms in a diamond to make it even harder, which may be useful in industrial applications that rely on synthetic cutting diamonds.

Researchers at the University of Tsukuba used computer calculations to design a new carbon-based material even harder than diamond. This structure, dubbed “pentadiamond” by its creators, may be useful for replacing current synthetic diamonds in difficult cutting manufacturing tasks.

Diamonds, which are made entirely of carbon atoms arranged in a dense lattice, are famous for their unmatched hardness among known materials. However, carbon can form many other stable configurations, called allotropes. These include the familiar graphite in pencil lead, as well as nanomaterials such as carbon nanotubes. The mechanical properties, including hardness, of an allotrope depend mostly on the way its atoms bond with each other. In conventional diamonds, each carbon atom forms a covalent bond with four neighbors. Chemists call carbon atoms like this as having sp3 hybridization. In nanotubes and some other materials, each carbon forms three bonds, called sp2 hybridization.

New breakthrough in ‘spintronics’ could boost high speed data technology

Scientists have made a pivotal breakthrough in the important, emerging field of spintronics—which could lead to a new high speed energy efficient data technology.

An international team of researchers, including the University of Exeter, has made a revolutionary discovery that has the potential to provide high speed, low power-usage for some of the world’s most well-used .

While today’s information technology relies on electronics that consumes a huge amount of energy, the electrons within can also transfer a form of angular momentum called .

Physicists Discover Exotic, New ‘Tetraquark’ Particle We’ve Never Seen Before

There’s a new exotic subatomic particle on the atom smasher. Physicists working with CERN’s Large Hadron Collider beauty (LHCb) collaboration have found a new form of the elusive four-quark particle called a tetraquark that they have never seen before.

The newly identified particle is made up of four quarks of the same flavour and is likely, scientists say, to be the first of a previously undiscovered class of particles.

The paper describing it has been uploaded to arXiv, and is yet to be peer-reviewed, but joins a growing body of evidence supporting the existence of exotic particles.

A three-dimensional phase diagram of heavy-fermion compound with competing quantum phases

URu2Si2 is a metal that belongs to the family of heavy-fermion compounds in which several quantum phases (e.g., magnetism and superconductivity) can compete or coexist. These metals exhibit small energy scales that are easy to tune, a characteristic that makes them ideal for testing new physical ideas and concepts.

For instance, researchers have often used these compounds to test theories related to , quantum criticality and unconventional superconductivity. Studying heavy-fermion metals could ultimately unveil new physical properties of other correlated-electron materials that have shown promise for a wide range of applications, such as .

A research team at the National Laboratory of High Magnetic Fields (LNCMI/CNRS) in France and Université Grenoble Alpes, in collaboration with researchers at Okayama University and Tohoku University in Japan, recently carried out a systematic investigation of URu2Si2 under a combination of high pressures and high magnetic fields. Their paper, published in Nature Physics, maps out a phase in the material that is so far poorly understood, delineating a complex three-dimensional phase diagram.

Fastest Laser Blast — 67 Quintillionths of a Second

face_with_colon_three Circa 2012

Scientists have been able to generate the world’s fastest laser pulse with a beam shot for 67 attoseconds (0.000000000000000067 seconds). This breaks the previous record of 80 attoseconds that was established in 2008. This could help engineers see extremely rapid quantum mechanical processes, like the movements of electrons during chemical reactions.

The researchers published their findings in the journal Optics Letters. This will allow the study of electron motions with attosecond pulses. The blast was obtained by sending pulses from a titanium-sapphire near-infrared laser through a system known as double optical gating (DOG) in which the gate concentrates the energy of extreme ultraviolet light pulses and focuses them on a cell filled with neon gas.

How Transparent Graphene Electrodes Could Aid Solar Cell Generation

A new technique of manufacturing graphene could revolutionize solar power by enabling the creation of ultra-lightweight, flexible solar panels.

A novel technique developed by researchers at the Michigan Institute of Technology (MIT) that allows for the creation of large sheets of graphene — a layer of single carbon atoms extracted from graphite — could have a significant impact on the development of future electronic devices.

In particular, the development could give a significant boost to the field of solar power where graphene is used as a replacement for indium tin oxide (ITO) in the creation of electrodes. The resultant transparent and light electrodes can bend up to 78 ⁰ — much more flexible than traditional ITO electrodes.

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