Wednesday, October 13, 2010

Limitless Ladder: Part 4: The Race to the "123" Compound

Let's start with an excerpt from D. Balasubramanian's review:

Not every chapter in [Limitless Ladder] reads positive. His comments on bureaucrats and supplicants read depressing; equally so in science, when he loses priority on discoveries. A compound his lab made over two years ago was suddenly found by someone else to be a superconductor at 90K.

Here's another from P. Rama Rao's review:

In 1986, Rao came close to winning the coveted Nobel Prize. A pair of scientists at IBM’s Swiss lab found a known insulating metal oxide was indeed a high-temperature superconductor. Rao had worked on an identical family of metal oxides a good 15 years earlier. Alas, his work did not concern exactly that aspect the IBM researchers happened to investigate, winning the Nobel in 1987. Rao agonised over this incident but did not let up in his unrelenting pursuit of excellence, going on to make important contributions to high-temperature superconductivity and to several other facets of the new chemistry of materials.

The excerpts from the two reviews hint at a deep sense of disappointment and agony felt by CNR for missing out on something important, ground-breaking, even Nobel-worthy. They hint at high drama. They hint at pathos.

Since I had read these reviews before I read Limitless Ladder, I was primed for CNR's own telling of this momentous story in his life. Here it is:

In December 1986, there was a major revolution in physical sciences. A high-temperature superconductor had been discovered. The material had broken the long-standing 23K barrier and became superconducting at 35K. I did not know much about it until I met Prof. P.W. Anderson ... who was visiting Bangalore for an international conference ... [Soon] after my lecture, Prof. Anderson asked me whether I knew about this new high-temperature superconductor. When I told him that I had no knowledge of it, he mentioned that the material was an oxide with lanthanum (La), copper (Cu), etc. I asked him whether by any chance, it was related to LaCuO4. When he said yes, I told him of the work we had done on this family of oxides many years earlier. My first paper on this family of materials with P. Ganguly had been published in 1971. We immediately went to my laboratory at IISc and spent two hours going through all my papers. We had already shown that La2CuO4 was antiferromagnetic. I started to worry as to how I could contribute to the exciting area of warm superconductors.

I had many sleepless nights, until we discovered two months later, one of the first liquid-nitrogen superconductors, by employing a novel strategy. Till then, all the superconductors required liquid helium. This new compound YBa2Cu3O7 (called 123), characterized independently in Bangalore (at the same time as Bell Labs and Beijing), became superconducting around 90K (above the liquid nitrogen temperature). ...

These paragraphs convey -- in their own understated way -- the excitement of doing important work, CNR's intense competitive streak -- "I had many sleepless nights." -- and a sense of "the race is on.

But, there's nothing here about the work's aftermath.

There's nothing here about who got the credit for the 123 compound (while CNR mentions some unspecified "independent" work at Bell Labs and Beijing, Wikipedia credits two American groups).

There's nothing here about CNR's "agonizing over this incident" nor about the "depressing" story of "[losing] priority over his discoveries."

So, we are left wondering about the reasons for CNR's agony. Was it about losing the race to the 123 compound? Was it about getting into the race late, because he did not know about Bednorz and Müller's work until Anderson told him about it? Was it about not having probed the low-temperature properties of this class of oxides in his earlier work (starting in the 1970s)? If so, was it about not having the right equipment to do this kind of work in the 1970s and the 80s? Or, was it about something else altogether?

We don't know.

And CNR has chosen to not talk about it. While we may respect his choice, I'm not sure if it's the right one, because it makes his autobiography incomplete.