Physicists Uncover New Mechanism Enabling Magnetism and Superconductivity to Co-exist in the Same Material

Current Wire Magnetism

Magnetism can be generated simply by passing a current through a wire, but how it interacts with other physical phenomena (such as superconductivity) is shrouded in mystery. Credit: University of Bath

Why Deep Freezing Iron-Based Materials Makes Them Both Magnetic and Superconducting

Physicists at the University of Bath, in collaboration with researchers from the USA, have uncovered a new mechanism for enabling magnetism and superconductivity to co-exist in the same material. Until now, scientists could only guess how this unusual coexistence might be possible. The discovery could lead to applications in green energy technologies and in the development of superconducting devices, such as next-generation computer hardware.

As a rule, superconductivity (the ability of a material to pass an electrical current with perfect efficiency) and magnetism (seen at work in fridge magnets) make poor bedfellows because the alignment of the tiny electronic magnetic particles in ferromagnets generally leads to the destruction of the electron pairs responsible for superconductivity. Despite this, the Bath researchers have found that the iron-based superconductor RbEuFe4As4, which is superconducting below -236°C, exhibits both superconductivity and magnetism below -258°C.

Physics postgraduate research student David Collomb, who was a key member of the research team led by Professor Simon Bending, explained: “There’s a state in some materials where, if you get them really cold – significantly colder than the Antarctic – they become superconducting. But for this superconductivity to be taken to next-level applications, the material needs to show co-existence with magnetic properties. This would allow us to develop devices operating on a magnetic principle, such as magnetic memory and computation using magnetic materials, to also enjoy the benefits of superconductivity.

“The problem is that superconductivity is usually lost when magnetism is turned on. For many decades, scientists have tried to explore a host of materials that have both properties in a single material, and material scientists have recently had some success fabricating a handful of such materials. However, so long as we don’t understand why the coexistence is possible, the hunt for these materials can’t be done with as fine a comb.

“This new research gives us a material that has a wide temperature range where these phenomena co-exist, and this will allow us to study the interaction between magnetism and superconductivity more closely and in great detail. Hopefully, this will result in us being able to identify the mechanism through which this co-existence can occur.”

In a study published in Physical Review Letters, the team investigated the unusual behavior of RbEuFe4As4 by creating magnetic field maps of a superconducting material as the temperature was dropped. To their surprise, they found the vortices (the points in the superconducting material where the magnetic field penetrates) showed a pronounced broadening near the temperature of -258°C, indicating a strong suppression of superconductivity as the magnetism turned on.

Gold Crystals

On the left: a crystal coated in gold — the gold coating allows the magnetic imaging tool to get within nanometers of the material’s surface. On the right: a magnetic picture of a segment of the crystal showing the vortices (dark holes) that were studied. Credit: University of Bath

These observations agree with a theoretical model recently proposed by Dr. Alexei Koshelev at Argonne National Laboratory in the USA. This theory describes the suppression of superconductivity by magnetic fluctuations due to the Europium (Eu) atoms in the crystals. Here, the magnetic direction of each Eu atom begins to fluctuate and align with the others, as the material drops below a certain temperature. This causes the material to become magnetic. The Bath researchers conclude that while superconductivity is considerably weakened by the magnetic effect, it is not fully destroyed.

“This suggests that in our material, the magnetism and superconductivity are held apart from each other in their own sub-lattices, which only minimally interact,” said Mr. Collomb.

“This work significantly advances our understanding of these rare coexisting phenomena and could lead to possible applications in the superconducting devices of the future. It will spawn a deeper hunt into materials that display both superconductivity and magnetism. We hope it will also encourage researchers in more applied fields to take some of these materials and make the next-generation computing devices out of them.

“Hopefully, the scientific community will gradually enter an era where we move from blue-sky research to making devices from these materials. In a decade or so, we could be seeing prototype devices using this technology that do a real job.”

Professor Bending added: “Our main result, that the onset of magnetism strongly suppresses superconductivity, is rather surprising and, on the face of it, appears to contradict previous measurements on very similar samples. However, RbEuFe4As4 is an extremely complex material in which the electrons and holes responsible for superconductivity exist in several separate bands. Each of these contributes a different amount to the superconducting state and interacts differently with the magnetic europium atoms. As a result, any observations can be very sensitive to the exact details of the measurement being made.”

Reference: “Observing the Suppression of Superconductivity in RbEuFe4As4 by Correlated Magnetic Fluctuations” by D. Collomb, S. J. Bending, A. E. Koshelev, M. P. Smylie, L. Farrar, J.-K. Bao, D. Y. Chung, M. G. Kanatzidis, W.-K. Kwok and U. Welp, Physical Review Letters.
DOI: 10.1103/PhysRevLett.126.157001

The American collaborators for this project were the Argonne National Laboratory, Hofstra University and Northwestern University.

5 Comments on "Physicists Uncover New Mechanism Enabling Magnetism and Superconductivity to Co-exist in the Same Material"

  1. Frosted Flake | June 9, 2021 at 10:27 pm | Reply

    Magnetism and superconductivity are USUALLY contradictory. Un-sorta-quote.

    Interesting. And the first time I ever heard of it. And I’m a 58 year old know it all.

    Maybe we ought to discuss this? I mean, in public. Superconductivity cancels magnetism? WHAT? What I know is a current causes magnetism. Show me that ain’t so.

    Pro tip. Never accept a new idea on one data point.

  2. BibhutibhusanPatel | June 10, 2021 at 2:48 am | Reply

    The typical iron compound shows magnetism at 37.16°K òr below temperature.Likely,the same material becomes superconductir at the tempeŕayure 15.1⁶°K or below.Here the limiting temperatures in two cases aŕe of sole importance.Both are important in the evolution and existànce òf galaxìes in the Universe.So the device ìs too impòrtant and precise can be used in perfect and typical goal oriented Space Works.Thanks to the author.

  3. BibhutibhusanPatel | June 10, 2021 at 2:53 am | Reply

    The typical iron compound shows magnetism at 37.16°K òr below temperature.Likely,the same material becomes superconductir at the tempeŕayure 15.1⁶°K or below.Here the limiting temperatures in two cases aŕe of sole importance.Both are important in the evolution and existànce òf galaxìes in the Universe.So the device ìs too impòrtant and precise can be used in perfect and typical goal oriented Space Works.Thanks to the author.As the device can function with certain extra effects simultaneousĺy wìth common use describes for mòre clùes.

  4. BibhutibhusanPatel | June 10, 2021 at 3:05 am | Reply

    The typical iron compound shows magnetism at 37.16°K òr below temperature.Likely,the same material becomes superconductir at the tempeŕayure 15.1⁶°K or below.Here the limiting temperatures in two cases aŕe of sole importance.Both are important in the evolution and existànce òf galaxìes in the Universe.So the device ìs too impòrtant and precise can be used in perfect and typical goal oriented Space Works.Thanks to the author.As the device can function with certain extra effects simultaneousĺy wìth common use describes for mòre clùes.While instrumentised is helpful in mutiple ways alined and axial to galaxy matter and proporties
    of astrphysics coreleted with time.

  5. The image shown states that a thin coating of gold was used to cover the crystal for imaging purposes.
    It is 100% likely that Gold had some effect on the results. It is also possible that a thin layer of gold would be a great place to remove single atoms of Gold.
    Theories exist (I accept them as facts by this point, the rest is just details) that state that many of the Noble Metals i.e. Gold lose metallic properties when removed from their clusters…which break down to single atoms at different #’s in the cluster. I think if less than 7 atoms of Rhodium and they seperate to single atoms, Gold is fickle, it will pair with only two atoms, BUT once that bond breaks the single atoms tighten up and elongate, with the mass and electron on both ends similar to wheels on an axle. The gold goes in to a HIGH SPIN STATE, in two dimensions instead of the normal 3.
    !! Similar 2 dimensional studies were recently published on carbon as well!!
    This drops the core temperature of the atom way down I believe where it becomes superconducting at ROOM TEMPERATURE.
    Apparently there is an abundance of these materials on Earth. They largely go unnoticed (even though they make up a portion of our own body) because they (2D matter) exist at different frequencies than 3D matter doesnt.
    So people, machines, other molecules must be TUNED to the correct frequency to interact with them….THEORY like I said, but a bit of digging will show unusually high amount of parallels between all these new superconductor studies being published and old knowledge published a decade ago, 50 years ago, 1000’s of years ago…its astounding, more like rediscoveries.
    Any insight is welcome, save the criticism, it’s obvious how little we still know about the universe,
    This high spin state material could be DARK MATTER is my postulation, called ORME In most literature and studies I have been into. Thanks.

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