The existence of a new kind of magnetism has been confirmed
www.newscientist.com
Altermagnets, theorised to exist but never before seen, have been measured for the first time and they could help us make new types of magnetic computers
  • DigitalMus@feddit.dk
    31·
    9 months ago

    Altermagnets are pretty interesting because their most defining feature is not the magnetic order in the materials. They look like ordinary antiferromagnets where the spins of adjacent atoms point in opposite direction and compensate each other, so no large magnetic fields are created. What differentiate altermagnets from antiferromagnets is how the electrons with different spin behave. When pulling current through altermagnets it will consist of purely spin up electrons along one crystal axis and purely spin down along orthogonal crystal axes. Thus the spin currents have a ‘alternating’ pattern, giving the name altermagnet. This is primarily exciting for the field of ‘spintronics’ which is all about creating technologies using spin currents.

    Not all altermagnets are equally interesting, many antiferromagnets can be reclassified to altermagnets but they are generally insulating. (fun fact the first ever measured and textbook antiferromaget MnF2 is actually altermagnetic) So materials discovery of new altermagnets is important to find metallic, semi-metallic or even super conducting altermagnets.

  • angrystego@lemmy.world
    5·
    9 months ago

    So if I understand correctly, both antiferromagnets and altermagnets can be packed together very tightly, unlike ferromagmets, which makes them potentionally better for use in computers. I didn’t really get the advantage altermagnets have compared to antiferromagnets and why they’re more suitable for spintronics. I’d appreciate if anyone could ELI5.

    • DigitalMus@feddit.dk
      51·
      9 months ago

      Imagine there are two balls, a red and a blue. You want to communicate to your friend rolling the only blue ball to them. In a ferromagnet there are only blue balls, in an antiferromagnet the blue and red balls are glued together and in an altermagnet there are both balls but they go in different directions so you just need to orient yourself correctly.

      The antiferromagnet can’t be used for spintronics, the ferromagnet can but big magnetic field disturb other parts in a circuit.