Suspended layers make a special superconductor

Phys.org  November 5, 2019 Researchers in the Netherlands created a suspended double layer of molybdenum disulfide with an ionic liquid on both sides that can be used to create an electric field across the bilayer. In the individual monolayer, such a field will be asymmetric, with positive ions on one side and negative charges induced on the other. However, in the bilayer, they could have the same amount of charge induced at both monolayers, creating a symmetrical system. The electric field that was thus created could be used to switch superconductivity on and off. This means that a superconducting transistor […]

Scientists finally find superconductivity in place they have been looking for decades

Phys.org  September 26, 2019 The biggest obstacle to making superconductors operate at higher temperatures and making superconductivity more robust has been the lack of a model. High-temperature superconductors are quantum materials, where electrons cooperate to produce unexpected properties. A team of researchers in the US (Stanford University, SLAC National Accelerator Laboratory) created a virtual version of a cuprate on a square lattice, like a wire fence with square holes where each virtual atom can accommodate at most two electrons that are free to jump or hop—either to their immediate neighbors on the square lattice or diagonally across each square. When […]

Light pulses provide a new route to enhance superconductivity

Phys.org  March 4, 2019 Under normal electron band theory, Mott insulators ought to conduct electricity, but they do not due to interactions among their electrons. An international team of researchers (Japan, Italy) used numerical methods to show that pulses of light could be used to turn these materials beyond simple conductors to superconductors due to an unconventional type of superconductivity known as “eta pairing” which is thought to involve repulsive interactions between certain electrons within the structure. The research provides new insights not only into the phenomenon of non-equilibrium dynamics but could lead to the development of new high-temperature superconductors…read […]

Physicists uncover new competing state of matter in superconducting material

Science Daily  January 2, 2019 Using ultrafast terahertz pump-probe a team of researchers in the US (Iowa State University, University of Alabama) found an unusual out-of-equilibrium Cooper pair nonlinear dynamics and a nonequilibrium state in iron pnictides. They identified long prebottleneck dynamics that are sensitive to both doping and temperature. According to the researchers the buildup of excitonic interpocket correlation between electron-hole quasiparticles quenches superconductivity after photoexcitation leading to a long-lived, many-quasiparticle excitonic state. Findings help create better superconducting electronics and energy-efficient devices…read more. TECHNICAL ARTICLE

Graphene on the way to superconductivity

Science Daily  November 9, 2018 Previously researchers at MIT showed that it is possible to generate a form of superconductivity in a system of two layers of graphene under very specific conditions using a complex method. Researchers in Germany have developed a simpler technique by heating silicon carbide crystal until silicon atoms evaporate from the surface, leaving first a single-layer of graphene on the surface, and then a second layer of graphene. The two graphene layers are not twisted against each other but lie exactly on top of each other. They argue that their two-dimensional flat band model and the […]

Superconductivity above 10 K in a novel quasi-one-dimensional compound

Phys.org  August 13, 2018 Researchers in China succeeded in synthesizing the new Q1D K2Mo3As3 compound whose Tc value exceeded 10 K. Bulk superconductivity below 10.4 K was confirmed by electrical resistivity, magnetic susceptibility, and heat capacity measurements. The K2Mo3As3 is the first MoAs-based superconductor and possesses the record Tc in all Q1D superconductors. This discovery indicates that Cr and Mo based Q1D superconductors may share some common underlying origins within the similar structural motifs and will help to uncover the exotic superconducting mechanism in low dimensional materials… read more. Open Access TECHNICAL ARTICLE