A little bit of high-Tc history

By Hamish Johnston

That’s Paul Grant (right) holding one of the high-temperature superconductor demonstration kits that he and his colleagues developed at IBM’s Almaden lab. The idea is that you fill the reservoir with liquid nitrogen and then place a magnet above the superconductor, where it will float.

The kit that Paul is holding was made in 1987 for IBM board members – and if you look at the photograph below you can see “IBM” embossed on the disc of a YBCO superconductor.

But as a 1987 New Scientist article by Grant points out, it’s not that difficult to make your own high-T_c material.

The article describes how Grant’s daughter Heidi (pictured in the clipping held by Grant) and her high-school classmates were able to make their own YBCO superconductor – and then float a magnet over it.

Reading the article I had a strong sense of deja vu. I had just been in a press conference where Kostya Novoselov was asked why graphene research took off like a rocket after he and Andre Geim worked out a way of making stand-alone sheets of the material. His answer was that it was fairly straightforward to make large high-quality samples of graphene and study its many properties.

But that’s where the similarity ends. Although physicists don’t understand everything about graphene, many properties have proven to be exactly as predicted by theory.

The same can’t be said about high-T_c superconductors, which have surprised and confounded physicists for 25 years. That was the subject of a talk today by the University of California’s Bob Dynes. “I will be surprised if there are no more surprises,” said Dynes.