Flawed but colorful diamonds are among the most sensitive detectors of magnetic fields known today, allowing physicists to explore the minuscule magnetic fields in metals, exotic materials and even human tissue. A team of physicists have now shown that these diamond sensors can measure the tiny magnetic fields in high-temperature superconductors, providing a new tool to probe these much ballyhooed but poorly understood materials.
Scientists at Ames Laboratory are revealing the...
Superconductor “recipes” are frequently tweaked by swapping...
An international team has recently unveiled a superconducting pairing mechanism in calcium-doped graphene. The pairing, which was using a angle-resolved photoemission spectroscopy method, is important because graphene is easily doped or functionalized with chemicals, allowing scientists to more fully explore the nature of superconductivity.
Nearly 30 years after the discovery of high-temperature superconductivity, many questions remain, but an Oak Ridge National Laboratory team is providing insight that could lead to better superconductors. Their work examines the role of chemical dopants, which are essential to creating high-temperature superconductors.
A breakthrough for the field of spintronics, a new type of technology which it is widely believed could be the basis of a future revolution in computing, has been announced by scientists in the U.K. The new study breaks new ground by showing, for the first time, that the natural spin of electrons can be manipulated, and more importantly detected, within the current flowing from a superconductor.
In two complementary studies, an international team of physicists has now established that superconductivity in high-temperature superconductors, known as cuprates, collapses at a maximum of -135 C due to the formation of charge-density waves. Consequently, in order to find superconductors that drop to zero resistance at realistic temperatures, materials scientists must search for substances that are not subject to charge-density waves.
High-temperature superconductors exhibit a frustratingly varied catalog of odd behavior, such as electrons that arrange themselves into stripes or refuse to arrange themselves symmetrically around atoms. Now two physicists propose that such behaviors, and superconductivity itself, can all be traced to a single starting point, and they explain why there are so many variations.
Scientists in Israel have taken a quantum leap toward understanding the phenomenon known as superconductivity: They have created the world’s smallest SQUID, a device used to measure magnetic fields, which has broken the world record for sensitivity and resolution.
Understanding superconductivity 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.
The decades-long effort to create practical superconductors moved a step forward with the discovery at Rice Univ. that two distinctly different iron-based compounds share common mechanisms for moving electrons. Samples from two classes of iron-based superconductors, pnictides and chalcogenides, employ similar coupling between electrons in their superconducting state.
Semiconductors have had a nice run, but for certain applications, such as astrophysics, they are being edged out by superconductors. Ben Mazin, asst. prof. of physics at the Univ. of California, Santa Barbara, has developed a superconducting detector array that measures the energy of individual photons.
A Binghamton Univ. scientist and his international colleagues report on the successful synthesis of the first superconductor designed entirely on the computer. The synthesized material, a novel iron tetraboride compound, is made out of two common elements, has a brand-new crystal structure and exhibits an unexpected type of superconductivity for a material that contains iron, just as predicted in the original computational study.
A theoretical study conducted by scientists at Japan’s National Institute of Materials Science reveals the possibility of developing a quantum material to transport zero-resistance edge current above room temperature. This capability, allowed by large spin-orbit coupling, will depend on the construction of a new class of topological materials that the researchers have designed.
An international collaboration at Lawrence Berkeley National Laboratory’s Advanced Light Source has induced high-temperature superconductivity in a toplogical insulator, an important step on the road to fault-tolerant quantum computing.
The stage is now set for superconductivity to branch out and meet some of the biggest challenges facing humanity today. This is according to a topical review, published in Superconductor Science and Technology, which explains how superconducting technologies can move out of laboratories and hospitals and address wider issues such as water purification, earthquake monitoring and the reduction of greenhouse gases.
Just like people, materials can sometimes exhibit “multiple personalities.” This kind of unusual behavior in a certain class of materials has compelled researchers at Argonne National Laboratory to take a closer look at the precise mechanisms that govern the relationships between superconductivity and magnetism.
Researchers from the RIKEN Center for Life Science Technologies and Chiba Univ. have developed a high-temperature superconducting wire with an ultrathin polyimide coating only 4 micrometers thick, more than 10 times thinner than the conventional insulation used for high-temperature superconducting wires. The breakthrough should help the development of more compact superconducting coils for medical and scientific devices.
A team led by Oak Ridge National Laboratory’s Amit Goyal, a former R&D Scientist of the Year, has demonstrated that superconducting wires can be tuned to match different operating conditions by introducing small amounts of non-superconducting material, or defects, that influences how the overall material behaves. A wire sample grown with this process exhibited new levels of performance in terms of engineering critical current density.
Scientists at Brookhaven National Laboratory have discovered an unexpected and anomalous pattern in the behavior of one high-performing class of HTS materials. In the new frontier of interface physics, two non-conducting materials can be layered to produce HTS behavior, with tantalizing and mystifying results.
Scientists at Brookhaven National Laboratory and other collaborating institutions have discovered a surprising twist in the magnetic properties of high-temperature superconductors, challenging some of the leading theories. In a new study, scientists found that unexpected magnetic excitations—quantum waves believed by many to regulate HTS—exist in both non-superconducting and superconducting materials.
In the search for understanding how some magnetic materials can be transformed to carry electric current with no energy loss, scientists have used an experimental technique to measure the energy required for electrons to pair up and how that energy varies with direction. The method measures energy levels as small as one ten-thousandth the energy of a single light photon.
The U.S. LHC Accelerator Program (LARP) has successfully tested a powerful superconducting quadrupole magnet that will play a key role in developing a new beam focusing system for CERN’s Large Hadron Collider (LHC). This advanced system, together with other major upgrades to be implemented over the next decade, will allow the LHC to produce 10 times more high-energy collisions than it was originally designed for.
A research team has found superconductivity in the solid form of a compound called carbon disulfide, CS2, which is sometimes used in liquid form as a chemical solvent or insecticide. Superconductivity is usually present in highly ordered molecular structures, but in carbon disulfide, superconductivity arises from a highly disordered state, which is rare. Even more strange is the magnetic state that precedes superconductivity.
Scientists from SLAC National Accelerator Laboratory and Stanford Univ. have used finely tuned x-rays at the Stanford Synchrotron Radiation Lightsource to pin down the source of a mysterious magnetism that appears when two materials are sandwiched together. Why is this mysterious? Neither material shows a hint of magnetism on its own.
In the superconducting state, electrons travel in so-called Cooper pairs through the crystal lattice. An energy gap accounts for the difference in energy needed to break up these pairs into free electrons. In high-temperature superconductors, a similar energy gap also occurs above the superconducting transition temperature: the pseudogap. A German-French research team has constructed a new model that explains how this pseudogap state forms.
Physicists at the U.S. Dept. of Energy's Ames Laboratory have discovered surprising changes in electrical resistivity in iron-based superconductors. The findings offer further evidence that magnetism and superconductivity are closely related in this class of novel superconductors.
Physicists at the University of Arkansas have collaborated with scientists in the United States and Asia to discover that a crucial ingredient of high-temperature superconductivity could be found in an entirely different class of materials. The team found that the way electrons form in superconductive material—known as the Zhang-Rice singlet state—was present in a chemical compound that is very different from conventional superconductors.
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