Research from North Carolina State Univ. finds that impurities can hurt performance, or possibly provide benefits, in a key superconductive material that is expected to find use in a host of applications, including future particle colliders. The size of the impurities determines whether they help or hinder the material’s performance.
Scientists at Yale Univ. have confirmed a 50-year-old, previously untested theoretical...
Carefully timed pairs of laser pulses at the Linac...
For more than a quarter of a century, high-temperature superconductors have perplexed scientists...
An international team of scientists has reported the first experimental observation of the quantum critical point (QCP) in the extensively studied “unconventional superconductor” TiSe2, finding that it does not reside as predicted within the superconducting dome of the phase diagram, but rather at a full GPa higher in pressure.
In extremely cold helium, downward flow into a “drain” forms a vortex that obeys the law of quantum mechanics, not classical mechanics (as with, say, water). Sometimes two vortexes interact and violently separate. Computer simulations suggest that after the vortexes pull apart, they develop ripples called “Kelvin waves” to quickly get rid of the energy. Now, for the first time, researchers have visual evidence that this actually happens.
Researchers in California have used a beam of intense ultraviolet light to look deep into the electronic structure of a material made of alternating layers of graphene and calcium. While it's been known for nearly a decade that this combined material is superconducting, the new study offers the first compelling evidence that the graphene layers are instrumental in this process. The finding could lead to super-efficient nanoelectronics.
Earlier this week, a team of U.S. cosmologists using the BICEP2 telescope at the South Pole said they have discovered the first direct evidence of the rapid inflation of the universe at the dawn of time. The finding was made possible, in part, by superconducting quantum interference devices (SQUIDs) designed at NIST.
A team of Univ. of Toronto physicists led by Alex Hayat has proposed a novel and efficient way to leverage the strange quantum physics phenomenon known as entanglement. The approach would involve combining light-emitting diodes (LEDs) with a superconductor to generate entangled photons and could open up a rich spectrum of new physics as well as devices for quantum technologies, including quantum computers and quantum communication.
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 mysteries of new materials using ultra-fast laser spectroscopy. Researchers recently used ultra-fast laser spectroscopy to examine and explain the mysterious electronic properties of iron-based superconductors. Seeing these dynamics is one emerging strategy to better understanding how these new materials work.
Superconductor “recipes” are frequently tweaked by swapping out elements or manipulating the valence electrons to strike the perfect conductive balance. Most high-temperature superconductors feature only one orbital impacting performance. But what about introducing more complex configurations? Now, Brookhaven National Laboratory’s physicists have combined atoms with multiple orbitals and precisely pinned down their electron distributions.
Modern electronics relies on utilizing the charge properties of the electron. The emerging field of atomtronics, however, uses ensembles of atoms to build analogs to electronic circuit elements. Physicists have built a superfluid atomtronic circuit that have allowed them to demonstrate a tool that is critical to electronics: hysteresis. It is the first time that hysteresis has been observed in an ultracold atomic gas.
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.
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