"We do not claim yet a local correlation between the pseudogap and superconductivity. We don't have experimental evidence strong enough to prove such a correlation. But establishing this connection will be an important direction of future study."
Read more at: http://phys.org/news/2012-11-atomic-resolution-images-fresh-insights-mysterious.html#jCp
For anyone well-acquainted with the idea of "high-temp" superconductors, cuprate compounds quickly come to mind. As of yet, cuprate superconductors are able to exist at relatively high temps (-100 degrees Celsius or below, yikes!). Of course, research is being done about possible superconductors that could work at, say, room temperature. That's where the pseudogap comes into play. As mentioned in the linked article, the pseudogap phase is a state of non-superconducting behavior found in superconductors (mostly cuprate) near the point when the superconductor should be in a proper environment for superconductivity.
The interesting part of the pseudogap phase is what was found by this international research team. The researchers noticed that, when studying samples (which become superconductors after sufficient doping) under a scanning tunneling microscope, the sample underwent interesting physical changes just as the superconductor moved from the pseudogap state to superconductivity. The researchers saw various nano-scale clusters of atoms accumulate as doping brought the sample closer and closer to the point of superconductivity. As the samples transitioned from pseudogap state to superconductivity, the researchers saw these clusters of atoms start to join together.
What does this remind you of? For me, it reminds me about the unit cells of crystalline solids. Crystalline solids form the unique shapes that they do because, on the atomic level, atoms or molecules line up into lattice structures, with the smallest repeated pattern called the unit cell.
Now, when the sample compounds reached superconductivity, the researchers saw the "clusters" of atoms fully connect with one another. A possible thought is that these clusters, when fully connected, form a lattice similar to that of crystalline solids. For crystalline solids, this kind of lattice led to rigid shapes in the macroscopic world. What if, for superconductors, the atoms form a similar lattice that allows for superconductivity? I am not saying that the lattice would need to be identical to those of crystalline solids, but I think it is reasonable to believe that they could be similar in concept. Frustratingly enough, this can all only be speculation, since very little is actually known about the pseudogap and superconductivity.
The interesting part of the pseudogap phase is what was found by this international research team. The researchers noticed that, when studying samples (which become superconductors after sufficient doping) under a scanning tunneling microscope, the sample underwent interesting physical changes just as the superconductor moved from the pseudogap state to superconductivity. The researchers saw various nano-scale clusters of atoms accumulate as doping brought the sample closer and closer to the point of superconductivity. As the samples transitioned from pseudogap state to superconductivity, the researchers saw these clusters of atoms start to join together.
What does this remind you of? For me, it reminds me about the unit cells of crystalline solids. Crystalline solids form the unique shapes that they do because, on the atomic level, atoms or molecules line up into lattice structures, with the smallest repeated pattern called the unit cell.
Now, when the sample compounds reached superconductivity, the researchers saw the "clusters" of atoms fully connect with one another. A possible thought is that these clusters, when fully connected, form a lattice similar to that of crystalline solids. For crystalline solids, this kind of lattice led to rigid shapes in the macroscopic world. What if, for superconductors, the atoms form a similar lattice that allows for superconductivity? I am not saying that the lattice would need to be identical to those of crystalline solids, but I think it is reasonable to believe that they could be similar in concept. Frustratingly enough, this can all only be speculation, since very little is actually known about the pseudogap and superconductivity.
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