Superconductivity is a rare physical state in which matter is able to conduct electricity without any resistance. It can only be found in certain materials, and even then it can only be achieved under controlled conditions of low temperatures and high pressures. New research from the Carnegie Institution hones in on the structural changes underlying superconductivity in iron arsenide compounds.
A research team led by the Univ. of Pittsburgh’s Jeremy Levy has discovered electrons that can “...
Synchrotron radiation facilities provide insights into the world of very small structures like...
Physicists have shown how heat can be used to control the magnetic properties of matter. The...
When a mirror reflects light, it experiences a slight push. This radiation pressure can be increased considerably with the help of a small superconducting island. The finding paves a way for the studies of mechanical oscillations at the level of a single photon, the quantum of light.
Add water to a half-filled cup and the water level rises. This everyday experience reflects a positive material property of the water-cup system. But what if adding more water lowers the water level by deforming the cup? This would mean a negative compressibility. Now, a quantum version of this phenomenon, called negative electronic compressibility (NEC), has been discovered.
Physicists have shown how heat can be exploited for controlling magnetic properties of matter. The finding helps in the development of more efficient mass memories. The result was published in Physical Review Letters. The international research group behind the breakthrough included Finnish researchers from the University of Jyväskylä and Aalto Univ.
A research team has investigated the electronic properties of the family of unconventional superconductors based on fullerenes, which have the highest known superconducting critical temperature among molecular superconductors, and was able to demonstrate the guiding influence of the molecular electronic structure in controlling superconductivity and achieving maximum Tc.
The pseudogap, a state characterized by a partial gap and loss of coherence in the electronic excitations, has been associated with many unusual physical phenomena in a variety of materials ranging from cold atoms to colossal magnetoresistant manganese oxides to high temperature copper oxide superconductors. Its nature, however, remains controversial due to the complexity of these materials and the difficulties in studying them.
High purity single crystals of superconducting material (CeCoIn5) with the highest observed superconducting temperature for a cerium-based material enabled investigation of the relationship among magnetism, superconductivity and disorder by strategic substitution of certain atoms with others (dopants) in the superconductor.
Taking our understanding of quantum matter to new levels, scientists at Los Alamos National Laboratory are exposing high-temperature superconductors to very high magnetic fields, changing the temperature at which the materials become perfectly conducting and revealing unique properties of these substances.
Researchers at SLAC National Accelerator Laboratory watched nanoscale semiconductor crystals expand and shrink in response to powerful pulses of laser light. This ultrafast “breathing” provides new insight about how such tiny structures change shape as they start to melt: information that can help guide researchers in tailoring their use for a range of applications.
A study published by researchers at Argonne National Laboratory provides theoretical evidence for a new effect that may lead to a way of measuring the exact temperature at which superconductivity kicks in and shed light on the poorly understood properties of superconducting materials above this temperature.
An international team of researchers has used infinitely short light pulses to observe ultrafast changes in the electron-level properties of superconductors, setting a new standard for temporal resolution in the field. The scientists liken the new technique to the development of high-speed film capture in the early days of photography.
Using ultracold atoms as a stand-in for electrons, a Rice Univ.-based team of physicists has simulated superconducting materials and made headway on a problem that's vexed physicists for nearly three decades. The research was carried out by an international team of experimental and theoretical physicists and appears online in Nature. The work could open up a new realm of unexplored science.
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.
Scientists have demonstrated a nanoscale memory technology for superconducting computing that could hasten the advent of an urgently awaited, low-energy alternative to power-hungry conventional data centers and supercomputers. In recent years, the stupendous and growing data demands of cloud computing, expanded Internet use, mobile device support and other applications have prompted the creation of large, centralized computing facilities.
A new type of nanowire crystals that fuses semiconducting and metallic materials on the atomic scale could lay the foundation for future semiconducting electronics. Researchers at the Univ. of Copenhagen are behind the breakthrough, which has great potential. The development and quality of extremely small electronic circuits are critical to how and how well future computers and other electronic devices will function.
Theorists and experimentalists working together at Cornell Univ. may have found the answer to a major challenge in condensed matter physics: identifying the smoking gun of why “unconventional” superconductivity occurs, they report in Nature Physics.
Massachusetts Institute of Technology researchers have discovered a new mathematical relationship—between material thickness, temperature and electrical resistance—that appears to hold in all superconductors. The result could shed light on the nature of superconductivity and could also lead to better-engineered superconducting circuits for applications like quantum computing and ultra-low-power computing.
An experiment at SLAC National Accelerator Laboratory provided the first fleeting glimpse of the atomic structure of a material as it entered a state resembling room-temperature superconductivity—a long-sought phenomenon in which materials might conduct electricity with 100% efficiency under everyday conditions.
A team of scientists has discovered an unusual form of electronic order in a new family of unconventional superconductors. The findingestablishes an unexpected connection between this new group of titanium-oxypnictide superconductors and the more familiar cuprates and iron-pnictides, providing scientists with a whole new family of materials from which they can gain deeper insights into the mysteries of high-temperature superconductivity.
A study at the SLAC National Accelerator Laboratory suggests for the first time how scientists might deliberately engineer superconductors that work at higher temperatures. In their report, a team of researchers explains why a thin layer of iron selenide superconducts at much higher temperatures when placed atop another material, which is called STO for its main ingredients strontium, titanium and oxygen.
Researchers studying iron-based superconductors are combining novel electronic structure algorithms with the high-performance computing power of the U.S. Dept. of Energy’s Titan supercomputer at Oak Ridge National Laboratory to predict spin dynamics, or the ways electrons orient and correlate their spins in a material.
A research team led by a Brown Univ. physicist has produced new evidence for an exotic superconducting state, first predicted a half-century ago, that can arise when a superconductor is exposed to a strong magnetic field. This new understanding of what happens when electron spin populations become unequal could have implications beyond superconductivity.
Research by an international team of scientists has uncovered a new, unpredicted behavior in a copper oxide material that becomes superconducting at relatively high temperatures. This new phenomenon presents a challenge to scientists seeking to understand its origin and connection with high-temperature superconductivity. Their ultimate goal is to design a superconducting material that works at room temperature.
Computer chips with superconducting circuits would be 50 to 100 times as energy efficient as today’s chips, an attractive trait given the increasing power consumption of the massive data centers that power Internet sites. Superconducting chips also promise greater processing power: Superconducting circuits that use so-called Josephson junctions have been clocked at 770 GHz, or 500 times the speed of the chip in the iPhone 6.
Mazhar Ali, a fifth-year graduate student in the laboratory of Bob Cava, the Russell Wellman Moore Professor of Chemistry at Princeton Univ., has spent his academic career discovering new superconductors, materials coveted for their ability to let electrons flow without resistance. While testing his latest candidate, the semimetal tungsten ditelluride (WTe2), he noticed a peculiar result.
Imagine being able to tune the properties of a solid material just by flashing pulses of light on it. That is one potential payoff of electrons and atoms interacting with ultrashort pulses of light. The technology of ultrafast spectroscopy is a key to understanding this phenomenon and now a new wrinkle to that technology, observations of electron self-energy, has been introduced by Lawrence Berkeley National Laboratory researchers.
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