Superconductivity

A result from the simulations of stacked graphene layers. The image depicts the so-called Berry curvature that confirms the topological character of the superconductivity. Credit: © Areg GhazaryanNew topological superconductivity in multilayered graphene sheets.Graphene is a strange material. Understanding its properties is both a fundamental question of science and a promising avenue for new technologies. A team of researchers from the Institute of Science and Technology Austria (ISTA) and the Weizmann Institute of…

Has the quest for room temperature superconductivity finally succeeded? Researchers at the University of Rochester (U of R), who previously were forced to retract a controversial claim of room temperature superconductivity at high pressures, are back with an even more spectacular claim. This week in Nature they report a new material that superconducts at room temperature—and not much more than ambient pressures. “If this is correct, it’s completely…

The two spheres represent holes in an ordered magnetic array of spins (illustrated with compasses). Due to this magnetic environment, the hole dopants bind in pairs. Credit: Christoph Hohmann, Munich Center for Quantum Science and TechnologyA team of scientists, including physicist Eugene Demler from ETH Zurich, for the first time, closely observed how magnetic correlations play a role in mediating hole pairing.Superconductivity only occurs in pairs. Therefore, in order for conductance without electrical resistance to…

MIT physicists have found a new way to switch superconductivity on and off in magic-angle graphene. This figure shows a device with two graphene layers in the middle (in dark gray and in inset). The graphene layers are sandwiched in between boron nitride layers (in blue and purple). The angle and alignment of each layer enables the researchers to turn superconductivity on and off in graphene with a short electric pulse. Credit: Courtesy of the researchers. Edited by MIT NewsApplying a quick electric pulse completely flips…

When electrons couple up, further quantum trickery makes superconductivity unavoidable. Normally, electrons can’t overlap, but Cooper pairs follow a different quantum mechanical rule; they act like particles of light, any number of which can pile onto the head of a pin. Many Cooper pairs come together and merge into a single quantum mechanical state, a “superfluid,” that becomes oblivious to the atoms it passes between.BCS theory also explained why mercury and most other metallic elements superconduct when cooled close to…

Electrons whizzing through a grid-like lattice don't behave at all like pretty silver spheres in a pinball machine. They blur and bend in collective dances, following whims of a wave-like reality that are hard enough to imagine, let alone compute.And yet scientists have succeeded in doing just that, capturing the motion of electrons moving about a square lattice in simulations that – until now – had required hundreds of thousands of individual equations to produce.Using artificial intelligence (AI) to reduce that task…

In 2020, Ranga Dias, a physicist at the University of Rochester, and his colleagues published a sensational result in Nature, featured on its cover. They claimed to have discovered a room-temperature superconductor: a material in which electric current flows frictionlessly without any need for special cooling systems. Although it was just a speck of carbon, sulfur, and hydrogen forged under extreme pressures, the hope was that someday the material would lead to variants that…

Engineers at Caltech observed an unusual phenomenon in twisted trilayer graphene.So-called “magic-angle twisted <span class="glossaryLink" aria-describedby="tt" data-cmtooltip="<div class=glossaryItemTitle>graphene</div><div class=glossaryItemBody>Graphene is an allotrope of carbon in the form of a single layer of atoms in a two-dimensional hexagonal lattice in which one atom forms each vertex. It is the basic structural element of other allotropes of carbon, including…

A team of physicists from UNLV’s Nevada Extreme Conditions Lab (NEXCL) used a diamond anvil cell, a research device similar to the one pictured, in their research to lower the pressure needed to observe a material capable of room-temperature superconductivity. Credit: Image courtesy of NEXCLLess than two years ago the science world was shocked by the discovery of a material capable of room-temperature superconductivity. Now, a team of University of Nevada Las Vegas (UNLV) physicists has upped the ante once again by…

Illustration of Andreev reflection between a superconductor and an atomically sharp metal tip. Credit: Aalto University / Jose LadoNew technique helps researchers understand unconventional superconductors.One of nature’s most fascinating quantum phenomena is superconductivity. When a superconducting material is cooled below its critical temperature, electricity can flow without any losses and magnetic fields are expelled.These remarkable properties make superconductors very useful in a wide range of applications including…