Move Over, Ladies! Diamonds Are an MRI’s Best Friend, Study Shows

Diamonds, it turns out, are good for more than engagement rings and lasers. A new study found there are some surprising things going on inside the carbon lattice that makes up the stone, characteristics that could pave the way for improvements in MRI machines and quantum information processing.

Published in Science Advances, the paper reports that some of the quantum properties of diamond, seen at the tiny scale of electrons and atomic nuclei, work differently than previously thought. Professor Carlos Meriles (City College of New York, The Graduate Center), postdoctoral researchers Daniela Pagliero and Jacob Henshaw, and previous Meriles lab postdoctoral researcher Pablo Zangara authored the study.

“Spin” is a property of subatomic particles, like the nuclei that make up the center of atoms or negatively-charged electrons. To conceptualize spin, one can imagine these particles having tiny, internal magnetic compasses. In diamonds, there are tiny, atomic-scale imperfections called NV- and P1-centers, and these can also have spin.

Because of their spin, these centers exert a very small, localized magnetic field on any carbons sitting next to them. As a result, these carbons become polarized—they align their own spin with that of the NV- and P1-centers. Scientists previously thought that these carbons couldn’t pass on their polarization to carbons further away from the imperfections; they thought it was a localized effect.

Sometimes, the new study reveals, this is not true.

“Our experiments demonstrate that these ideas are not valid when the concentration of electron spins is sufficiently high,” Meriles said. The researchers found that the carbons near the defects and the carbons farther away “communicate efficiently because groups of electron spins serve as effective linkers to move around otherwise isolated nuclear spin polarization.”

To the authors’ knowledge, the theory framework they developed to explain this phenomenon is new.

In an MRI machine, where signal strength depends on polarization, this polarization-communication could be very valuable, Meriles explained. The research could lead to cheaper systems and portable machines. Spectroscopy machines, used for biology and pharmacology research, operate on similar principles and could benefit as well. And in the computing world, the results could help scientists attempting to use networks of electron spins to manipulate and store quantum information.