Using a new type of large-scale magnet conductor, scientists in Japan have recently achieved an electrical current of 100,000 A, a world record. The conductor, which was built using yttrium-based high-temperature superconducting tapes for high mechanical strength, is a prototype for using in a future fusion reactor.
When a superconductor is exposed to a magnetic...
Using a scanning tunneling microscope to visualize...
For his doctoral dissertation, Yu Chen developed a...
An international research team led by scientists in Barcelona has developed a material which guides and transports a magnetic field from one location to the other, similar to how an optical fiber transports light or a hose transports water. The magnetic hose consists of a ferromagnetic cylinder covered by a superconductor material, a surprisingly simple design made possible by complicated theoretical calculations and experimentation.
A breakthrough has been made in identifying the origin of superconductivity in high-temperature superconductors, which has puzzled researchers for the past three decades. Researchers in the U.K. have found that ripples of electrons, known as charge density waves or charge order, create twisted ‘pockets’ of electrons in these materials, from which superconductivity emerges.
Quantum criticality, the strange electronic state that may be intimately related to high-temperature superconductivity, is notoriously difficult to study. But a new discovery of “quantum critical points” could allow physicists to develop a classification scheme for quantum criticality—the first step toward a broader explanation.
Quantum criticality, the strange electronic state that may be intimately related to high-temperature superconductivity, is notoriously difficult to study. But a new discovery of “quantum critical points” could allow physicists to develop a classification scheme for quantum criticality, the first step toward a broader explanation.
An international team of researchers from the USA and Japan, including Takao Sasagawa at Tokyo Institute of Technology, have uncovered a two-stage transition in lanthanum-strontium-copper-oxide high-temperature superconductors (LSCOs), leading to the first complex phase diagram of the behavior of LSCOs. This research could improve understanding of high-temperature superconductivity under magnetic fields.
Scientists at the U.S. Dept. of Energy’s Argonne National Laboratory have discovered a previously unknown phase in a class of superconductors called iron arsenides. This sheds light on a debate over the interactions between atoms and electrons that are responsible for their unusual superconductivity.
For the first time, scientists have a clearer understanding of how to control the appearance of a superconducting phase in a material, adding crucial fundamental knowledge and perhaps setting the stage for advances in the field of superconductivity. The paper focuses on a calcium-iron-arsenide single crystal, which has structural, thermodynamic and transport properties that can be varied through carefully controlled synthesis.
A fully functional quantum computer is one of the holy grails of physics. Unlike conventional computers, the quantum version uses qubits (quantum bits), which make direct use of the multiple states of quantum phenomena. When realized, a quantum computer will be millions of times more powerful at certain computations than today’s supercomputers.
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 prediction in physics and improved the energy storage time of a quantum switch by several orders of magnitude. High-quality quantum switches are essential for the development of quantum computers and the quantum Internet.
Carefully timed pairs of laser pulses at the Linac Coherent Light Source have been used to trigger superconductivity in a promising copper-oxide material and immediately take x-ray snapshots of its atomic and electronic structure as superconductivity emerged. The results of this effort have pinned down a major factor behind the appearance of superconductivity, and it hinges around “stripes” of increase electrical charge.
For more than a quarter of a century, high-temperature superconductors have perplexed scientists who seek to understand the physical phenomena responsible for their unique properties. Thanks to a new study by Argonne National Laboratory, researchers have identified and solved at least one paradox in the behavior of high-temperature superconductors.
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.
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