Quantum Computing Breakthrough in Atom Control Found by Accident Will Open Up 'Treasure Trove of Discoveries'

A team of scientists in Australia claim to have stumbled on a breakthrough discovery that will have "major implications" for the future of quantum computing.

Describing the find as a "happy accident," engineers at the University of New South Wales Sydney found a way to control the nucleus of an atom using electric fields rather than magnetic fields—which they have claimed could now open up a "treasure trove of discoveries and applications."

Quantum computing expands on understandings of tech by basing research on quantum theory—analysing how energy works at atomic and subatomic levels.

Electric fields make it easier to control the spin of atoms compared to magnetic fields, which are difficult to confine to small spaces as they have a "wide area of influence."

The study, published in Nature, solves a problem in finding a way to control nuclear spins with electricity, first suggested back in 1961 by the magnetic resonance expert and Nobel Laureate Nicolaas Bloembergen, the team said.

"This discovery means that we now have a pathway to build quantum computers using single atom spins without the need for any oscillating magnetic field for their operation," elaborated UNSW Scientia Professor of Quantum Engineering Andrea Morello.

"Moreover, we can use these nuclei as exquisitely precise sensors of electric and magnetic fields, or to answer fundamental questions in quantum science. 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."

Prof. Morello added: "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."

The team said they initially set out to perform nuclear magnetic resonance on a single atom of antimony, which is an element that possesses a large nuclear spin.

Dr. Serwan Asaad, an co-author of the study, said the initial aim had been to "explore the boundary between the quantum world and the classical world set by the chaotic behaviour of the nuclear spin." He said the "curiosity-driven project" quickly showed signs of academic promise.

Elaborating on what happened next, another co-author, Dr. Vincent Mourik, added: "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. This puzzled us for a while, until we had a 'eureka moment' and realised that we were doing electric resonance instead of magnetic resonance.

"We [made] 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 field to be quite strong, so we applied a lot of power to the antenna, and we blew it up."

The test showed nuclear electric resonance is a "local microscopic phenomenon" and the electric field effectively distorted the atomic bonds around the nucleus, causing it to shift.

Nuclear magnetic resonance is a technique used in a variety of scientific fields, such as medicine, chemistry and mining. The use of electric fields over magnetic fields could shake things up.

Prof. Morello said: "Doctors use it to see inside a patient's body in great detail, while mining companies use it to analyse rock samples. This all works extremely well, but for certain applications, the need to use magnetic fields to control and detect the nuclei can be a disadvantage.

"Performing magnetic resonance is like trying to move a particular ball on a billiard table by lifting and shaking the whole table. We'll move the intended ball, but we'll also move all the others. The breakthrough of electric resonance is like being handed an actual stick to hit the ball exactly where you want it."