Scientists discover new type of magnet

Scientists discover new type of magnet
In a normal magnetic material, dense magnetic moments try to align with their neighbors (left). By contrast, in a singlet-based material, unstable magnetic moments pop in and out of existence, and stick to one another in aligned clumps (right). Credit: Lin Miao, NYU's Department of Physics

A team of scientists has discovered the first robust example of a new type of magnet—one that holds promise for enhancing the performance of data storage technologies.

This "singlet-based" magnet differs from conventional magnets, in which small magnetic constituents align with one another to create a . By contrast, the newly uncovered singlet-based magnet has fields that pop in and out of existence, resulting in an unstable force—but also one that potentially has more flexibility than conventional counterparts.

"There's a great deal of research these days into the use of magnets and to improve data storage technologies," explains Andrew Wray, an assistant professor of physics at New York University, who led the research team. "Singlet-based magnets should have a more sudden transition between magnetic and non-magnetic phases. You don't need to do as much to get the material to flip between non-magnetic and strongly magnetic states, which could be beneficial for power consumption and switching speed inside a computer.

"There's also a big difference in how this kind of magnetism couples with electric currents. Electrons coming into the material interact very strongly with the unstable magnetic moments, rather than simply passing through. Therefore, it's possible that these characteristics can help with performance bottlenecks and allow better control of magnetically stored information."

The work, published in the journal Nature Communications, also included researchers from Lawrence Berkeley National Laboratory, the National Institute of Standards and Technology, the University of Maryland, Rutgers University, the Brookhaven National Laboratory, Binghamton University, and the Lawrence Livermore National Laboratory.

The idea for this type of magnet dates back to the 1960s, based on a theory that stood in sharp contrast to what had long been known about conventional magnets.

A typical magnet contains a host of tiny "magnetic moments" that are locked into alignment with other magnetic moments, all acting in unison to create a magnetic field. Exposing this assembly to heat will eliminate the magnetism; these little moments will remain—but they'll be pointing in random directions, no longer aligned.

A pioneering thought 50 years ago, by contrast, posited that a material that lacks magnetic moments might still be able to be a magnet. This sounds impossible, the scientists note, but it works because of a kind of temporary magnetic moment called a "spin exciton," which can appear when electrons collide with one another under the right conditions.

"A single spin exciton tends to disappear in short order, but when you have a lot of them, the theory suggested that they can stabilize each other and catalyze the appearance of even more spin excitons, in a kind of cascade," Wray explains.

In the Nature Communications research, the scientists sought to uncover this phenomenon. Several candidates had been found dating back to the 1970s, but all were difficult to study, with magnetism only stable at extremely low temperatures.

Using , X-ray scattering, and theoretical simulations, the researchers established a link between the behaviors of a far more robust magnet, USb2, and the theorized characteristics of singlet-based magnets.

"This material had been quite an enigma for the last couple of decades—the ways that magnetism and electricity talk to one another inside it were known to be bizarre and only begin to make sense with this new classification," remarks Lin Miao, an NYU postdoctoral fellow and the paper's first author.

Specifically, they found that USb2 holds the critical ingredients for this type of magnetism—particularly a quantum called "Hundness" that governs how electrons generate magnetic moments. Hundness has recently been shown to be a crucial factor for a range of quantum mechanical properties, including superconductivity.

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Journal information: Nature Communications

Citation: Scientists discover new type of magnet (2019, February 7) retrieved 23 September 2019 from
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User comments

Feb 09, 2019
Virtual Quantum Information

This newly uncovered singlet-based magnet has fields that pop in and out of existence
resulting in an unstable force
also one that potentially has more flexibility than conventional counterparts

This will give a new meaning
this virtual world
as these magnetic fields pop in and out of existence
the information held in these magnetic fields
will literally disappear as this field disappears as virtual photons

Our information will certainly be secure
in its virtual world
Until someone hacks this virtual world

Feb 10, 2019
Curious and Curiouser

A material that lacks magnetic moments is able to be a magnet.
temporary magnetic moment, spin excitons
which appear when electrons collide with one another under the right conditions
A single spin exciton disappears in short order
when you have a lot of them
they stabilize each other
Catalyze the appearance, they cascade even more spin excitons

As this needs more investigation
this raises the possibility
of increasingly powerful magnetic fields
while these magnetic fields
flit in and out of existence
individual spin excitons
in individual material
as one flips out of existence
another flips into existence
so only half the spin excitons
are temporally out of existance
at anyone time
in an aligned fields of millions of this material
Resulting in a powerful perfectly aligned field

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