Science Daily September 21, 2020 Strontium ruthenate (Sr2RuO4) has stood as the leading candidate for a spin-triplet superconductor for 26 years. Using resonant ultrasound spectroscopy an international team of researchers (USA – Cornell University, Florida State University, Germany, Japan) measured the entire symmetry-resolved elastic tensor Sr2RuO4 through the superconducting transition. They found a thermodynamic discontinuity in the shear elastic modulus which implies that the superconducting order parameter has two components, a two-component p-wave order parameter. As this order parameter appears to have been precluded by recent NMR experiments, they suggest that two other two-component order parameters are now the prime […]
Tag Archives: Superconductors
Closely spaced hydrogen atoms could facilitate superconductivity in ambient conditions
Phys.org February 3, 2020 An international team of researchers (Switzerland, USA – University of Illinois, Oak Ridge National Laboratory, Poland) conducted neutron scattering experiments on zirconium vanadium hydride at atmospheric pressure and at temperatures from -450 degrees Fahrenheit to as high as -10 degrees Fahrenheit and observed hydrogen-hydrogen atomic distances in the metal hydride, as small as 1.6 angstroms, compared to the 2.1 angstrom distances predicted for these metals. Computer simulations of the data proved conclusively that the unexpected spectral intensity occurs only when distances between hydrogen atoms are closer than 2.0 angstroms. The findings could possibly facilitate superconductivity at […]
Physicists make graphene discovery that could help develop superconductors
EurekAlert August 1, 2019 An international team of researchers (USA – Rutgers University, Japan) studied twisted bilayer graphene, created by superimposing two layers of graphene and slightly misaligning them. This creates a “twist angle” that results in a moiré pattern which changes rapidly when the twist angle changes and have a dramatic effect on the electronic properties of the material. This is because the moiré pattern slows down the electrons that conduct electricity in graphene and zip past each other at great speeds. At a twist angle of about 1.1 degrees – the so-called magic angle – the electrons come […]
Novel insulators with conducting edges
Eurekalert June 1, 2018 An international team of researchers (Switzerland, Spain, USA – Princeton University, Germany, France) has predicted a new class of topological insulators, called “higher-order topological insulators”, that have conducting properties on the edges of crystals rather than on their surface. The conducting edges are extraordinarily robust. If an imperfection gets in the way of the current, it simply flows around the impurity, if the crystal breaks, the new edges automatically conduct current and in theory electricity can be conducted without any dissipation. They have proposed tin telluride as the first compound to show these novel properties. The […]
Topological insulator ‘flips’ for superconductivity
Science Daily April 30, 2018 Using a novel “flip-chip” technique an international team of researchers (USA – University of Illinois, Japan) prepared single-crystalline Bi2Se3 films with predetermined thicknesses in terms of quintuple layers (QLs) on top of Nb substrates fresh from in situ cleavage. Measurements of the film surface disclosed superconducting gaps and coherence peaks of similar magnitude for both the topological surface states and bulk states and revealed key characteristics relevant to the mechanism of coupling between the topological surface states and the superconducting Nb substrate. This new sample preparation method opens many new avenues in research, building a […]
Bringing a hidden superconducting state to light
Science Daily February 16, 2018 An international team of researchers (Germany, USA – Brookhaven National Laboratory, UK) has detected a hidden state of electronic order in a layered material containing lanthanum, barium, copper, and oxygen (LBCO). When cooled to a certain temperature and with certain concentrations of barium, LBCO is known to conduct electricity without resistance, but now there is evidence that a superconducting state occurs above this temperature too. The discovery could help design better high-temperature superconductors… read more. TECHNICAL ARTICLE