Monday, March 07, 2016

Unidentified Superconducting Objects

The search for new superconductors has been going on for decades, because the potential promise of room temperature superconductors (with useful properties, like high critical fields, high critical currents, chemical stability, the ability to be integrated in some way into wires, ribbons, or tapes) is so enormous.  Littering the metaphorical laboratory floor are various claims over the years of "unidentified superconducting objects" - a term attributed to Paul Chu to describe one-off, irreproducible hints of 200-300 K superconductivity, often features in resistivity or magnetization that look like they could originate in some unknown impurity phase of an already complex material.  I was reminded of this by a paper that showed up on the arxiv last night.  Most likely this will fade away, but these things are always intriguing.  Extraordinary claims require extraordinary evidence, of course.


8 comments:

Anonymous said...

The typography makes my eyes bleed. Also, what's with listing formation pressures in units of kbar/cm^2? Pressure/area is a unit I've never encountered.

Douglas Natelson said...

Anon - Yeah, there are a bunch of issues, and a couple of the photos look like purported images of bigfoot. Ahh, but if it were the real thing.... :-)

Anonymous said...

I love how he keeps saying that he can't share details or data because the patent is pending...

Douglas Natelson said...

Anon@5:52, yeah. Once the patent is filed and priority is established, why not make it easy for others to confirm? Of course, given the protracted legal fight about YBCO (Paul Chu published first in PRL along with colorful stories about obscuring the formula in the review copies of the manuscript, but Bell Labs w/ Batlogg eventually got the patent - http://www.nature.com/nature/journal/v403/n6766/full/403121b0.html), there is a long tradition of caginess in the field.

Douglas Natelson said...

Just to clarify: This particular paper is almost certainly not reporting a result that will hold up, and there are many problems with the manuscript, which isn't really written like a scientific paper. It can be fun to imagine, though.

Anonymous said...

https://www.youtube.com/watch?v=5yUeSJC18Lo

Heumpje said...

Glad you clarified your viewpoint on this paper, 'cause I started to doubt after reading your post...

Heumpje said...

And yes, it is nice to imagine. I'm teaching SC to third year undergrads right now and this is one of the regular questions/interests they have.