Condensed matter on the public stage, and not in a good way

This week, condensed matter physics has been getting far more broad public attention than usual, and while in the abstract I like our discipline getting noticed, this is definitely not how I’d have preferred it to happen.

First, more fun re Ranga Dias.  Fresh off renewed controversy about claims of room temperature superconductivity in Lu-N-H at high pressures (claims of reproduction of the effect seem unreliable to me), it’s come out that this paper, already under an “expression of concern”, is being retracted.  This has been widely reported - see here (hurray for student journalism) and here and here for example.  It is abundantly clear that data fabrication/copying has taken place here.  Between this, the other retraction, and the clear evidence of thesis content plagiarism, it’s hard to see any signs of credibility remaining.  

Then there is the claim via preprints (here, here) of room temperature superconductivity at ambient pressure in a lead oxide compound from investigators in Korea.  Cutting to the chase:  it is very unlikely, in my view, that this pans out, for multiple reasons.  Extraordinary claims hardly ever hold up.  There are multiple weird issues with the data in the figures (e.g., magnetic susceptibility data that shows up in both papers with the same units but axes that differ in magnitude by a factor of 7000 - which numbers are reliable, if either?  Resistivity that seem bizarrely large (0.01 Ohm-cm is bigger than the Mott-Ioffe-Regel limit - again, are the units right?).  A specific heat that doesn’t reach 3R at high temperatures.  Not clear of the resistance is really zero in the nominally superconducting part of the V-I curves.).  That said, if the video and the not-crazy-scale susceptibility data are trustworthy, this stuff is very diamagnetic, more so than graphite, which is quite unusual.  At least the authors do provide a comparatively straightforward synthesis recipe, so replication attempts should clear this up in a week or two.  

None of this is thaaaaaaat unusual, by the way.  There are claims of weird superconductivity at some rate.  It’s easy to screw up measurements, especially in inhomogeneous materials.  Unfortunately, social media (esp the site formerly known as twitter) drastically amplifies this stuff.  I assume Michio Kaku is going to be on tv any second now talking about how this will change the world.  Hopefully responsible journalists will be effective at pointing out that a non-reviewed preprint on the arxiv is not conclusive.  

I’m traveling, so updates will be sparse, but I will try to keep an eye on the comments.