Scientists discover new, 3rd form of magnetism that may be the 'missing link' in the quest for superconductivity

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A researcher at the University of Nottingham in the UK, who works under a postdoctoral position, stated to Live Science, "Ferromagnetism, where the tiny magnetic fields, which you can think of as small compass arrows on an atomic scale, all point in the same direction. And antiferromagnetism, where the neighboring magnetic fields point in opposite directions - you can picture that more like a chessboard where the tiles switch regularly from white to black."

The electric current in a flow must have electrons spinning in one of two ways, and these spins can align with or against its magnetic field to store or transmit information, making it the foundation of magnetic memory.

A novel type of magnetism

This structure has a configuration that exists somewhere in between, with optimal situations. Each individual magnetic moment points the opposite direction from its neighbor, similar to an antiferromagnetic material. However, each unit is slightly tilted relative to the adjacent magnetic atom, resulting in some ferromagnetic-like qualities.

A doctoral student from the University of Nottingham stated, "However, because these materials have a net magnetism, that information is also easily lost when a magnet is wiped over it."

Related: "A power stronger than gravity is present within the Earth's core": How magnetism trapped itself within our planet

On the other hand, antiferromagnetic materials are harder to manipulate for information storage. The reason is that they have a net zero magnetism, but this also means that information in these materials is more secure and can be transmitted faster. "Altermagnets have the speed and resilience of an antiferromagnet, but they also have this important property of ferromagnets called time reversal symmetry breaking," Dal Din said.

This fascinating property explores the symmetry of objects as they move forward and backward through time. "For instance, gas particles scatter randomly, colliding and occupying the space," Amin said. "If you reverse time, that same behavior remains unchanged."

This means that symmetry is preserved. However, because electrons have both a quantum spin and a magnetic moment, reversing time — and, therefore, the direction of travel — flips the spin, which breaks the symmetry. "If you look at those two electron systems — one moving forward in time normally and one where you're going backwards to get back to the original state — they look different, so the symmetry is broken," Amin explained. "This allows certain electrical phenomena to occur."

Unlocking the Mystery of Superconductivity's Elusive Pieces

A physics professor at the University of Nottingham used a technique called photoemission electron microscopy to take a picture of the structure and magnetic properties of a material called manganese telluride, which researchers once thought was antiferromagnetic.

"The way we see magnetism depends on the polarization of the X-rays we use," Amin explained. Circularly polarized X-rays helped reveal the distinct magnetic domains that develop when time reversal symmetry breaks, while horizontally or vertically polarized X-rays allowed the team to determine the direction of the magnetic moments within the material. By putting the results of both experiments together, the researchers created a map of the different magnetic domains and structures in the altermagnetic material for the first time.

The team then created a series of altermagnetic devices using a method that involved controlling the internal magnetic structures through a process that involved heating and cooling them in a controlled manner.

We were able to create these unusual swirling patterns in both six-sided and triangle-shaped devices," Amin said. "These vortices are becoming more popular in spintronics research, because researchers believe they might be able to use them to carry information, so this was a positive achievement for building a functional device.

The study authors stated that the ability to both image and manipulate this new form of magnetism could revolutionize the design of next-generation memory devices, offering increased operational speeds, enhanced resilience, and greater user convenience.

Altermagnetism will also aid in the development of superconductivity," Dal Din said. "For quite a while, there's been a gap in the symmetries between these two fields, and this class of magnetic material that has long evaded discovery turns out to be the missing piece in the puzzle.