A new frontier for studying 2-D matter is provided by planar collections of electrons at the surface of transition-metal-oxide (TMO) materials, in which high electron densities give rise to interactions that are stronger than in semiconductors. Scientists hope to find exotic phenomena in these highly-interactive electron environments and one of the leaders in this effort is James Williams, a new fellow at the Joint Quantum Institute.
Research from North Carolina State Univ. shows that a type of modified titania, or titanium...
Physicists studying the effects of embedding...
New measurements of atomic-scale magnetic behavior in iron-based superconductors by researchers...
Thanks to a $1.5 million innovation award from the Gordon and Betty Moore Foundation, Rice Univ. physicist Emilia Morosan is embarking on a five-year quest to cook up a few unique compounds that have never been synthesized or explored. Morosan is no ordinary cook; her pantry includes metals, oxides and sulfides, and her recipes produce superconductors and exotic magnets.
The search for zero-resistance conductors that can operate at realistic temperatures has been frustrated by the inability to understand high-temperature superconductors, particularly their magnetic structure. Researchers have done this at the atomic scale for the first time with a so-called strongly correlated electron system of iron telluride. Previously, magnetic information was provided by neutron diffraction, which is imprecise.
Physicists have identified the “quantum glue” that underlies a promising type of superconductivity—a crucial step towards the creation of energy superhighways that conduct electricity without current loss. The research, published online in the Proceedings of the National Academy of Sciences, is a collaboration between the Univ. of Illinois at Chicago, Cornell Univ. and Brookhaven National Laboratory.
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 field, a surface current creates a magnetic field that cancels the field inside the superconductor. This phenomenon, known as the Meissner-Ochsenfeld effect, was first observed in 1933. In a research first, scientists have succeeded in measuring an analogue of the Meissner effect in an optical crystal with ultracold atoms. This validates theoretical predictions dating back more than 20 years.
Using a scanning tunneling microscope to visualize the electronic structure of the oxygen sites within a superconductor, a Binghamton Univ. physicist and his colleagues say they have unlocked one key mystery surrounding high-temperature superconductivity. The team found a density wave with a d-orbital structure, which is a pattern new to this type of superconductor and they may be found in all cuprates.
For his doctoral dissertation, Yu Chen developed a novel way to fabricate superconducting nanocircuitry. However, the extremely small zinc nanowires he designed did some unexpected things, including demonstrating dissipation characteristics though only to be present in normal states. After long and careful work, which involved both experimental and theoretical efforts, researchers have found an explanation that fits.
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.
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