A new class of high-temperature superconductors:
According to Steven Kivelson, a theoretical physicist at Stanford, "[there exist] enough similarities that it's a good working hypothesis that they're parts of the same thing." However, not everyone hopes the mechanism is the same. Philip Anderson, a Nobel Laureate and theoretical physicist at Princeton, says that an entirely new mechanism of superconductivity would be far more important than if they mimicked the current understanding of superconductivity. "If it's really a new mechanism, God knows where it will go," says Anderson.
Let's hope.
These are materials composed of five elements. There are tens of millions of subsets containing five elements (and many more variations in the ratios of the elements). We've barely scratched the surface in finding and characterizing possible phases. The previous unexpected high Tc material was a simple binary compound (magnesium diboride, Tc = 40 K).
I wonder if the first material was found by automated screening. This sort of combinatorial chemistry is well suited to high throughput robotic experimentation.
Just how close are nanotubes to superconducting? ISTR that lengthwise, they were supposed to be incredible conductors, and across the grain, excellent resistors.
Way cool. Years ago I was fascinated with the hypothetical room-temperature superconductors in Niven's "Ringworld." That, and the ridiculously sharp wire that was only a molecule or two thick.
Another fascinating property of superconductors, if I remember correctly, is that they also are temperature superconductors--they have the same temperature everywhere. Is that true, or it is it true of all superconductors?
Another fascinating property of superconductors, if I remember correctly, is that they also are temperature superconductors--they have the same temperature everywhere. Is that true, or it is it true of all superconductors?
It's not true at all. In fact, it's one of those scientific mistakes Niven's stories have propagated.
In reality, the thermal conductivity of a superconductive material decreases as it is cooled below the transition temperature. The paired electrons are in a condensed state with very low entropy, and as such cannot carry heat.
One of the applications of high Tc superconductors is as current carrying leads to connect low Tc superconductors to a hotter outside environment. The high Tc lead leaks much less heat than (say) copper or aluminum would.