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Blobrana


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RE: SUPERFLUIDITY
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A PhD student from the London Centre for Nanotechnology has won a prize for solving a decade-long mystery central to understanding modern magnetic systems.
Andrew Walters has won the 2009 Marshall Stoneham Prize, a newly established prize awarded annually to an outstanding PhD thesis in the area of condensed matter and materials physics.
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Blobrana


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Boojum
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What is a boojum?
Is it: a particularly dangerous variety of snark; a bizarre cactus-like tree endemic to Baja California in Mexico; or a geometrical pattern sometimes seen on the surface of superfluid helium-3?
In fact it's all three. Fans of Lewis Carroll will recall that in his poem The Hunting of the Snark, boojums are the most feared of all snarks. Meagre and hollow, but crisp-tasting beasts, they inhabit desolate valleys - a bit like the Mexican tree. Carroll's boojums cause those who venture too close to "softly and suddenly vanish away" - a fate that also befalls helium's superfluidity when a boojum appears.

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Blobrana


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Scientists at the Johannes Gutenberg University Mainz have, for the first time, succeeded in rendering the spatial distribution of individual atoms in a Bose-Einstein condensate visible. Bose-Einstein condensates are small, ultracold gas clouds which, due to their low temperatures, can no longer be described in terms of traditional physics but must be described using the laws of quantum mechanics.

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Blobrana


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University of Arizona scientists experimenting with some of the coldest gases in the universe have discovered that when atoms in the gas get cold enough, they can spontaneously spin up into what might be described as quantum mechanical twisters or hurricanes.
The surprising experimental results agree with independent numerical simulations produced by collaborating scientists at the University of Queensland in Australia. The Arizona and Queensland researchers are reporting the results of the research in the journal Nature (October 16, 2008).

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Blobrana


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superconductors
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Scientists have studied superconductors and superfluids for decades. Now researchers have drawn the first detailed picture of the way a superfluid influences the behaviour of a superconductor. In addition to describing previously unknown superconductor behaviour, these calculations could change scientists' understanding of the motion of neutron stars.

Source: Washington University in St. Louis

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Blobrana


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Fermionic quantum gasses
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Innsbruck Physicists of the EUROCORES Programme EuroQUAM achieve breakthrough with fermionic quantum gasses

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Blobrana


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MIT physicists have taken a step toward understanding the puzzling nature of high-temperature superconductors, materials that conduct electricity with no resistance at temperatures well above absolute zero.
If superconductors could be made to work at temperatures as high as room temperature, they could have potentially limitless applications. But first, scientists need to learn much more about how such materials work.
Using a new method, the MIT team made a surprising discovery that may overturn theories about the state of matter in which superconducting materials exist just before they start to superconduct. The findings are reported in the February issue of Nature Physics.

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Blobrana


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Even though the lightest known metals in the universe, lithium (Li) and beryllium (Be), do not bind to one another under normal atmospheric or ambient pressure, an interdisciplinary team of Cornell scientists predicts in the Jan. 24 issue of Nature that Li and Be will bond under higher levels of pressure and form stable Li-Be alloys that may be capable of superconductivity. Superconductivity is the flow of electricity with zero resistance.
The Inorganic, Bioinorganic and Organometallic Chemistry program at the National Science Foundation (NSF) supported the research because little work had been done to predict the properties of metals under high pressure.
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"We found that chemists working on inorganic compounds and inorganic reactions under high pressure were interested in the predictions and felt it would stimulate useful interactions between theorists and experimentalists" - NSF Program Manager Michael Clarke.

Of the four stable Li-Be alloys predicted by the scientists' computational study, the alloy with the ratio of one Li atom to one Be atom (LiBe) shows the greatest potential for superconducting applications.
A most unexpected finding in the study is the predicted existence of two-dimensional electron gas layers within a tightly compressed three-dimensional LiBe compound.

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Blobrana


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Superconductivity
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When Eric Hudson was introduced to high-temperature superconductivity as a graduate student, it was still, so to speak, a hot topic.
The phenomenon, discovered in the 1980s, reflects the fact that if you develop the right types of compounds, you can create electrical conductors that are completely resistance-free at temperatures well above the threshold for conventional superconductors.

"With conventional systems, you get to about 25 degrees Kelvin [-415? F] and then plateau. With high-temperature superconductivity, you were suddenly at 90 degrees Kelvin" - Eric Hudson, now the Class of 1958 Assistant Professor of Physics at MIT

That figure is well above the mark at which nitrogen gas turns liquid. This meant you could create devices like the high-powered electromagnets used in many MRI scanners without having to use costly liquid helium to cool the magnets' coils to superconducting temperatures. (Helium, which liquefies at a hyper-frigid 4 degrees above absolute zero, is a must for conventional superconducting devices.)
More exciting yet, the discovery seemed to signal that room-temperature superconductivity was on its way. This triggered claims that problems like electricity line -losses--the often-hefty amount of power lost to resistance in electrical transmission networks--would soon -disappear.

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Blobrana


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Bose-Einstein Condensate
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Quantum Ferrofluid: A Bose-Einstein Condensate of Tiny Magnets
Tiny magnetic atoms of chromium display superfluidity and the possibility of exotic quantum phases.

 It has long been known that contrary to the common sense notion that like charges repel electrons in solids tend to pair up at low temperatures to conduct electricity without heating the wire, a phenomenon known as superconductivity.

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