12 March 2020

Serendipitous Physics Discovery

A group of physicists attempted to use a magnetic field to influence the spin of an atomic nucleus.

Fortunately, they screwed, up, and blew up the antenna generating the magnetic field for the experiment.

In so doing, they subjected the nucleus to an electrical field, rather than a magnetic one, and when they saw the results, they realized that they had accidentally confirmed Bloembergen's theorem, which had remained unproven for over 50 years:
A group of scientists have accidentally proven a near 60-year old theory correct, thanks to a botched lab experiment.

Nicolaas Bloembergen, the late Dutch-American physicist who won the Nobel Prize for his contributions to laser spectroscopy, previously predicted that it was possible to control the nucleus of a single atom with electric fields in 1961. His idea, however, was never experimentally proven and was left largely forgotten until now.

………

Asaad and his colleagues set about probing a single atom of antimony, a metalloid element, fabricated on a silicon wafer with nuclear magnetic resonance. To do this, the team had to place the device in a strong magnetic field. They generated the magnetic field by applying an electric current to a superconducting magnet and directed it towards the atom’s nucleus using a specialised antenna.

"However, once we started the experiment, we realised that something was wrong. The nucleus behaved very strangely, refusing to respond at certain frequencies, but showing a strong response at others," said co-author Vincent Mourik, another postdoctoral researcher at the USNW Sydney, working in the same department.

Eventually they realised they had accidentally destroyed the antenna by cranking up the strength of the magnetic field. "What happened is that we fabricated a device containing an antimony atom and a special antenna, optimized to create a high-frequency magnetic field to control the nucleus of the atom. Our experiment demands this magnetic field to be quite strong, so we applied a lot of power to the antenna, and we blew it up!" Asaad said.

With the antenna borked, all that was being transmitted was an electric field instead. The researchers may have failed to induce nuclear magnetic resonance in the antimony nucleus but they had managed to get it to interact with just an electric field instead, proving Bloembergen’s theory. Results from the "failed" experiment have been published in research paper in Nature.

"I have worked on spin resonance for 20 years of my life, but honestly, I had never heard of this idea of nuclear electric resonance," said Andrea Morello, a professor of quantum physics at the USNW Sydney. "We 'rediscovered' this effect by complete accident - it would never have occurred to me to look for it. The whole field of nuclear electric resonance has been almost dormant for more than half a century, after the first attempts to demonstrate it proved too challenging."
I believe that Isaac Asimov once said that, "The most exciting phrase to hear in science, the one that heralds new discoveries, is not 'Eureka' but 'That's funny."

I agree.

0 comments :

Post a Comment