Monday, February 15, 2010

High-Tc Superconductors Are Very Kinky - Update 8

Looks like the cuprate high-Tc superconductors are kinkier than we originally thought!

In the compilation that I've done so far, we first discovered the 70 meV "kink", or band dispersion renormalization. Later on, came another kink at a significantly higher energy scale, at ~350 meV. Now comes news of another kink. This time, due to improved resolution using laser-based ARPES, a lower energy kink has been observed at about 8 meV below the gap.

Two publications/preprints have reported on this. The first one[1] reports that this kink seen in optimally-doped Bi2212 is tied to the optical phonon mode. The second one[2] appears to be reporting the nature of this kink over a wide doping range, and showing that it becomes stronger in the underdoped range. I said "appears", because I couldn't see the PDF document of this preprint on ArXiv. It won't open for me.

So now there are THREE kinks in the band dispersion of these cuprates! Anyway, both of these have been added to my original blog entry.


[1] J.D. Rameau et al. Phys. Rev. B v.80, p.184513 (2009)

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