While most magnets have two poles (north and south, or positive and negative), recent advances in quantum mechanics have revealed an “octupolar order,” writes Phys.org, where a pattern of particles in a crystalline structure “behaves as if it has eight magnetic poles rather than the familiar two.”
Now, a team led by quantum physicists at the University of Toronto has established a new method for observing quantum magnetic states using light to probe the atomic vibrations produced as electrons spin. The work is a critical first step toward harnessing multipolar magnetism for practical technologies, including next-generation data storage and computing devices.
“We identified new signatures of a hidden type of magnetic state which cannot be detected using ordinary probes,” says Arun Paramekanti, a professor in the Department of Physics and the Center for Quantum Information & Quantum Control in the Faculty of Arts & Science at the University of Toronto, and senior author of a study published in Physical Review Letters that describes the findings.
“Our research opens up the possibility for using higher-order magnets in several applications including controllable read-write memory elements found in everyday computers….”
By directing a special type of rotating light at magnetic materials, the team observed a clear optical fingerprint of the otherwise hidden magnetic order…. The findings offer a new tool for uncovering and manipulating previously inaccessible forms of magnetism, opening new avenues for quantum technology development.