Altermagnets

Researchers at the S N Bose National Centre for Basic Sciences have discovered a novel phenomenon in chromium antimonide (CrSb) — a rare class of magnetic material called an altermagnet. Altermagnets combine the benefits of ferromagnets and antiferromagnets, with unique electron behavior but no net external magnetism.

About Altermagnets

• Altermagnets are a novel class of magnetic materials that combine the benefits of ferromagnets (spin splitting) and antiferromagnets (zero net magnetization). Though they show no external magnetism, their internal electron spin behaviors make them highly promising for spintronics—technologies that manipulate electron spin rather than charge. Their unique properties, such as directional spin polarization and high thermal stability, open up exciting possibilities in future electronics.

  Properties of Altermagnets

  1.Altermagnets defy conventional norms by embodying a dual nature—resembling antiferromagnets with zero net magnetization and ferromagnets with non-relativistic spin splitting.
  2.This unique behavior emerges from the intricate interplay of atoms within the crystal structure. Additionally, altermagnets exhibit a unique spin polarization. The term “spin polarization” means that a preponderance of electron spins tends to align in a particular direction.
  3.The spin polarization is noteworthy in altermagnets because it occurs in the physical arrangement of atoms (real space) and in the momentum space, where the distribution of electron spins in the material is considered.
  4.The researchers believe that altermagnets could have a pivotal role in spin caloritronics, a field of research that explores the interplay between spin and heat flow, which are not achievable with ferromagnets or antiferromagnets.
  5.This field has potential applications in developing new technologies for information processing and storage.

  Altramagnetism in Chromium Antimonide
  Among the known altermagnets, chromium antimonide (CrSb) is truly remarkable.
  It is metallic, with the magnetic order sustaining up to more than two times that of room temperature and the largest altermagnetic spin-splitting, equivalent to more than 30 times that of room temperature.
  CrSb is one of the very few materials known to exhibit direction-dependent conduction polarity property and, notably, the first Altermagnet to do so.
  These outstanding attributes make CrSb the most promising altermagnetic candidate for practical applications.
  CrSb is made of earth-abundant and non-toxic elements, making it an environmentally friendly option for future electronics. Combined with its altermagnetic properties.... Read more at:

   

  Why its important

• Simplified Device Architectures: With both p-type and n-type behavior in one material, engineers can potentially design devices (like thermoelectrics or spin-based logic circuits) without needing heterostructures or doping gradients .

• Environmental Advantage: Cr and Sb are abundant and non-toxic, making CrSb an eco-friendly choice for next-generation electronics .

• Altermagnetic Edge: CrSb uniquely combines antiferromagnetic order (no net magnetization), strong non-relativistic spin splitting, and directional conduction properties—making it a prime candidate for spin caloritronics, where spin and heat currents are manipulated together.

  What are altermagnets used for?

• Altermagnets, with their unique magnetic properties—combining zero net magnetization and strong spin polarization—have promising applications mainly in the field of spintronics and spin caloritronics. These include:

• Generating and controlling spin-polarized currents without stray magnetic fields, enabling energy-efficient information processing and storage.

• Developing ultrafast memory devices that operate at terahertz frequencies.

• Creating spin-filter tunnel junctions for advanced magnetic sensors and memory elements.

• Enabling novel thermoelectric and spin-heat devices through their unique interaction of spin and heat currents.

• Beyond electronics, magnetic properties and magnetic measuring techniques related to altermagnets also find uses in broader areas such as metallurgy and chemistry, for understanding material properties and improving processes.