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A Material Found To Carry Current In a Way Never Before Observed (phys.org)
An anonymous reader quotes a report from Phys.Org: Scientists at the Florida State University-headquartered National High Magnetic Field Laboratory have discovered a behavior in materials called cuprates that suggests they carry current in a way entirely different from conventional metals such as copper. The research, published today in the journal Science, adds new meaning to the materials' moniker, "strange metals." Cuprates are high-temperature superconductors (HTS), meaning they can carry current without any loss of energy at somewhat warmer temperatures than conventional, low-temperature superconductors (LTS). Although scientists understand the physics of LTS, they haven't yet cracked the nut of HTS materials. Exactly how the electrons travel through these materials remains the biggest mystery in the field.
For their research on one specific cuprate, lanthanum strontium copper oxide (LSCO), a team led by MagLab physicist Arkady Shekhter focused on its normal, metallic state -- the state from which superconductivity eventually emerges when the temperature dips low enough. This normal state of cuprates is known as a "strange" or "bad" metal, in part because the electrons don't conduct electricity particularly well. Scientists have studied conventional metals for more than a century and generally agree on how electricity travels through them. They call the units that carry charge through those metals "quasiparticles," which are essentially electrons after factoring in their environment. These quasiparticles act nearly independently of each other as they carry electric charge through a conductor. But does quasiparticle flow also explain how electric current travels in the cuprates? At the National MagLab's Pulsed Field Facility in Los Alamos, New Mexico, Shekhter and his team investigated the question. They put LSCO in a very high magnetic field, applied a current to it, then measured the resistance. The resulting data revealed that the current cannot, in fact, travel via conventional quasiparticles, as it does in copper or doped silicon. The normal metallic state of the cuprate, it appeared, was anything but normal.
For their research on one specific cuprate, lanthanum strontium copper oxide (LSCO), a team led by MagLab physicist Arkady Shekhter focused on its normal, metallic state -- the state from which superconductivity eventually emerges when the temperature dips low enough. This normal state of cuprates is known as a "strange" or "bad" metal, in part because the electrons don't conduct electricity particularly well. Scientists have studied conventional metals for more than a century and generally agree on how electricity travels through them. They call the units that carry charge through those metals "quasiparticles," which are essentially electrons after factoring in their environment. These quasiparticles act nearly independently of each other as they carry electric charge through a conductor. But does quasiparticle flow also explain how electric current travels in the cuprates? At the National MagLab's Pulsed Field Facility in Los Alamos, New Mexico, Shekhter and his team investigated the question. They put LSCO in a very high magnetic field, applied a current to it, then measured the resistance. The resulting data revealed that the current cannot, in fact, travel via conventional quasiparticles, as it does in copper or doped silicon. The normal metallic state of the cuprate, it appeared, was anything but normal.
Multiple posts, all idiots, and the freaking Article doesn't even link the free, actually readable link to the story.
All I see here anymore are political whining, Team trolling, paid positions, and bullshit.
The first actual science in a while, and no interest.
Wow.
Here's a link to ArXiv, and the original pdf:
https://arxiv.org/abs/1705.058...
Truth isn't Truth - Guliani
While HTS conductors are superconducting at 77K (liquid nitrogen) they will always work better the colder they are. That is why the new 32T all superconducting magnet at the NHMFL is submerged in a bath of liquid helium at 4.2K. Additionally, the HTS conductors are pretty expensive at $80 per meter. Apart from some really high field solenoids and other fairly rare magnet applications, there really isnt much of a killer app for HTS conductors. The utilities have been working on very high current density cables in the past but I am not aware of any ongoing programs right now. For reference I will refer to a ReBCO conductor made by a company called Superpower that makes tapes that are 4mm wide and 0.1 mm thick. Keep in mind the actual SC layer is only 0.001 mm thick: No background field and at 4 K you can run well over 1000 A through a tape with no loss At 32 T and 4 K maybe 250 A or higher depending on field angle And at 77K with no background field maybe only 200 A
power transmission lines are unlikely to use liquid helium for cooling, but liquid nitrogen can be generated isolated from the atmosphere and cooled on site for use, that is why the op you responded to specifically mentioned power transmission and mag-lev
A common term in superconductivity is "critical surface." The 3 axis are current, field, and temperature. If you are under the surface, the conductor is superconducting, if above, it is not. If you had say a superconductor that had a critical temperature of 78 K in the field you are running it at, yes its resistance is zero but it wont be able to carry any significant current. What use is that? The point of superconductors is to move a lot of current (DC) with no loss. FYI superconductors do not have 0 impedance when carrying AC.