Tag Archives: superconductivity

Cesium atoms shaken, not stirred, to create elusive excitation in superfluid

Scientists discovered in 1937 that liquid helium-4, when chilled to extremely low temperatures, became a superfluid that could leak through glass, overflow its containers, or eternally gush like a fountain.

Future Nobel laureate Lev Landau came along in 1941, predicting that superfluid helium-4 should contain an exotic, particle-like excitation called a roton. But scientists, including Landau, Nobel laureate Richard Feynman and Wolf Prize recipient Philippe Nozières have debated what structure the roton would take ever since. (more…)

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Opposing phenomena possible key to high-efficiency electricity delivery

The coexistence of two opposing phenomena might be the secret to understanding the enduring mystery in physics of how materials heralded as the future of powering our homes and communities actually work, according to Princeton University-led research. Such insight could help spur the further development of high-efficiency electric-power delivery.

Published in the journal Science, the findings provide a substantial clue for unraveling the inner workings of high-temperature superconductors (HTS) based on compounds containing copper and oxygen, or copper oxides. Copper-oxide high-temperature superconductors are prized as a material for making power lines because of their ability to conduct electricity with no resistance. It’s been shown that the material can be used to deliver electrical power like ordinary transmission lines, but with no loss of energy. In addition, typical superconductors need extremely low temperatures of roughly -243 degrees Celsius (-405 degrees Fahrenheit) to exhibit this 100-percent efficiency. A copper oxide HTS, however, can reach this level of efficiency at a comparatively toasty -135 degrees Celsius (-211 degrees Fahrenheit), which is achievable using liquid nitrogen. (more…)

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A Superconductor-Surrogate Earns Its Stripes

Berkeley Lab Study Reveals Origins of an Exotic Phase of Matter

Understanding superconductivity – whereby certain materials can conduct electricity without any loss of energy – has proved to be one of the most persistent problems in modern physics. Scientists have struggled for decades to develop a cohesive theory of superconductivity, largely spurred by the game-changing prospect of creating a superconductor that works at room temperature, but it has proved to be a tremendous tangle of complex physics.

Now scientists at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) have teased out another important tangle from this giant ball of string, bringing us a significant step closer to understanding how high- temperature superconductors work their magic. Working with a model compound, the team illuminated the origins of the so-called “stripe phase” in which electrons become concentrated in stripes throughout a material, and which appears to be linked to superconductivity. (more…)

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A New Tool to Attack the Mysteries of High-Temperature Superconductivity

Berkeley Lab researchers use an ultrafast laser to better understand high-temperature superconductors

Superconductivity, in which electric current flows without resistance, promises huge energy savings – from low-voltage electric grids with no transmission losses, superefficient motors and generators, and myriad other schemes. But such everyday applications still lie in the future, because conventional superconductivity in metals can’t do the job.

Although they play important roles in science, industry, and medicine, conventional superconductors must be maintained at temperatures a few degrees above absolute zero, which is tricky and expensive. Wider uses will depend on higher-temperature superconductors that can function well above absolute zero. Yet known high-temperature (high-Tc) superconductors are complex materials whose electronic structures, despite decades of work, are still far from clear. (more…)

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Disappearing and Reappearing Superconductivity Surprises Scientists

Washington, D.C. — Superconductivity is a rare physical state in which matter is able to conduct electricity—maintain a flow of electrons—without any resistance. This phenomenon can only be found in certain materials at low temperatures, or can be induced under chemical and high external pressure conditions. (more…)

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IBM Honors the 25th Anniversary of High-Temperature Superconductivity

*IBM scientists, J. Georg Bednorz and K. Alex Muller, discovered the first successful high-temperature superconductor using a breakthrough ceramic material*

ZURICH – 18 Apr 2011: Twenty-five years ago IBM scientists, J. Georg Bednorz and K. Alex Muller altered the landscape of physics when they observed superconductivity in an oxide material at a temperature 50 percent higher(1), (-238 deg C, -397 deg F) than what was previously known. This discovery opened an entirely new chapter in the field of physics and earned them the Nobel Prize for Physics in 1987.

Their now seminal paper titled, “Possible High Tc Superconductivity in the Ba – La – Cu – O System”(2) was received by the peer-reviewed journal Zeitschrift fur Physik B on 17 April 1986. (more…)

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Under Pressure: Germanium

Washington, D.C. — Although its name may make many people think of flowers, the element germanium is part of a frequently studied group of elements, called IVa, which could have applications for next-generation computer architecture as well as implications for fundamental condensed matter physics.

New research conducted by Xiao-Jia Chen, Viktor Struzhkin, and Ho-kwang (Dave) Mao from Geophysical Laboratory at Carnegie Institution for Science, along with collaborators from China, reveals details of the element’s transitions under pressure. Their results show extraordinary agreement with the predictions of modern condensed matter theory. (more…)

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