Eric A. Cornell: Never resting on his (Nobel) laurels

Most people can point to one or more events in their lives that have forever altered the course or circumstances of their being. For physicist Eric A. Cornell, surely one of those was being awarded the 2001 Nobel Prize in Physics.

Cornell shared the prize that year with University of Colorado/JILA/National Institute of Standards and Technology (NIST) colleague Carl Wieman, and Wolfgang Ketterle of the Massachusetts Institute of Technology. The three researchers were lauded for having achieved Bose-Einstein condensation in a gas of rubidium atoms at very low temperature, and for fundamental studies of the properties of such condensates.

Asked what it was like to win the Nobel Prize so early in his scientific career, Cornell replies, “Very often, [winning a Nobel] is kind of like a punctuation mark at the end of a career, and then one goes and gives talks and sits on blue ribbon commissions and so on. And those are all important things to do. I did give a lot of talks and sat on some commissions, but at the time I won I was 39 years old, and that is really too young to become a professional Nobel laureate.”

Indeed, work on Bose-Einstein condensates (BECs) would consume another 15- to 20-years’ worth of work in Cornell’s lab. In BECs, he, Wieman, and Ketterle produced an exotic new form of matter for further investigation, work that has since unlocked complex quantum phenomena like superfluidity and superconductivity, with potential applications in areas like advanced atomic clocks, ultra-sensitive sensors, and quantum computing.

The condensates were long predicted to be achievable. In 1924, Indian physicist Satyendra Nath Bose made theoretical calculations regarding light particles. He sent his results to Albert Einstein who, in turn, extended the theory to a certain type of atom, predicting that if a gas of such atoms were cooled to a very low temperature, they would suddenly gather in the lowest possible energy state. The term “condensates” derives from the phenomenon’s similarity to the formation of drops of liquid from a gas.

In 1995, Cornell and his fellow laureates succeeded in achieving this extreme state of matter. Cornell and Wieman produced a pure condensate of about 2,000 rubidium atoms at 20 nK (nanokelvin), which is 0.00000002 degrees above absolute zero. Ketterle performed corresponding experiments with sodium atoms.

After receiving the Nobel, Cornell says he happily spent a few years being “a sort of ambassador for physics,” but after a couple more rounds of Nobel Prize winners being announced, he saw it was time to turn his attention back on his work.

“I was grateful to the field for the recognition,” he says. “But I also realized that that was not a sustainable lifestyle or a sustainable career. One of the things that I really wanted to think about in a very self-conscious way is [that] you can win a Nobel Prize, and then you think ‘It’s only worth doing experiments that will win me a second one.’ And that’s not a very productive way to do physics, you know.”

And then disaster struck.

Somehow, through a cut or a scratch perhaps, Cornell had contracted an invasive and deadly flesh-eating streptococcal infection. He went to the hospital on 24 October 2004 because of a gnawing and worsening pain in his left shoulder, never suspecting that the next day doctors would be forced to remove entirely the shoulder and his left arm. His torso required skin grafts.

Barely clinging to life, Cornell was placed in a medically induced coma. He would not return home until December of that year.

Cornell receiving his Nobel Prize from His Majesty King Carl XVI Gustaf of Sweden on 10 December 2001. Photo credit: Copyright © The Nobel Foundation 2001 / Hans Mehlin.

“When I got out of the hospital, my travel sort of had a step-function downward,” he recalls on a note of very dark humor, “I spent a lot of time not doing physics or traveling, but physical therapy and other boring things. But I got through that eventually.”

He went back to the lab. Of the years spent working on BECs, Cornell says he is proud of the work he and his graduate students have achieved. “But it’s also the case that I wanted to start something dramatically new, which is the precision metrology branch of my research. That has ramped up to the point where it kind of squeezed out the cold atoms stuff.”

Cornell is referring to his work with CU-Boulder physicist Jun Ye and others to determine the shape of the electron’s charge distribution to unprecedented precision—a measure that could facilitate discovery of new subatomic particles. 

The Standard Model in physics, it seems, cannot explain the dominance of matter over anti-matter in our universe. The imbalance suggests undiscovered physics, and many extensions to the Standard Model seek to explain the imbalance by predicting the existence of new particles.

But finding new subatomic particles is no mean feat, requiring multibillion dollar facilities like the Large Hadron Collider (LHC) at CERN that was used to detect the Higgs boson. 

Cornell and his colleagues say that the fluctuations of the fields associated with undiscovered particles can interact with known particles making small modifications to their properties, for example, inducing an electric dipole moment of the electron (eEDM). The size of the induced eEDM is dependent on the masses of the new particles.

To date, no eEDM has been detected, but having presented the most precise measurement yet of the eEDM using electrons confined inside molecular ions, subjected to a huge intra-molecular electric field, the team contends it has reached, with tabletop capability, sensitivity to new particle detection beyond the direct reach of the LHC or any other near- or medium-term particle collider.

“That’s very much on the horizon,” Cornell says. “The experiments we’re doing here and other eEDM-type experiments around the world—they’re sensitive to stuff that accelerators can’t get to. And we’re looking at another factor of 10 in sensitivity over the next few years. And so, yes, I’m very excited about that.

“I’m happy that over the years since the Nobel I’ve pursued a mix of short- and long-term projects,” Cornell continues.  “If I had strictly gone with the ‘go big or go home’ philosophy back in 2001, that probably would have been the last you ever heard from me.”

William G. Schulz is the Managing Editor of  Photonics Focus.