A New Variant of Magnetism Promises More Powerful Memory Devices
New research has unveiled two or three types of magnetism, introducing the possibility of a highly sought-after magnetic property. While early compass users may have perceived magnets as mystical, the scientific understanding of magnetism has evolved. In addition to ferromagnetism and antiferromagnetism, a third type, altermagnetism, has been identified, challenging previous descriptions of magnetic behavior.
Understanding Magnetism’s Complexity
Magnetism arises from the spins of electrons rather than large-scale electric currents or changing fields. Electron spins, unlike planetary rotations, exhibit subatomic behaviors that contribute to magnetic moments.
Although individual electron spins typically align randomly, in some instances, they synchronize to produce a significant magnetic field, as seen in ferromagnetic materials like iron.
Antiferromagnetism and the Discovery of Altermagnetism
Antiferromagnets, discovered in 1933, feature atoms with magnetic spins opposite their neighbors. However, their behavior is only apparent in an external magnetic field, leading to unique conductivity changes with potential applications.
Altermagnets, a recent discovery, initially appear similar to antiferromagnets, with internal spins opposing neighboring spins. Yet, their rotational symmetry results in spin polarization, creating alternating bands. This characteristic bridges the properties of ferromagnets and antiferromagnets, promising enhanced magnetic memory recorders, particularly in spintronics.
Applications in Spintronics and Beyond
Spintronics, which utilizes electron spin states for information transfer, has long been researched with ferromagnets. However, their bulk magnetism poses scalability challenges. Antiferromagnets circumvent this issue but lack specific desired spin-dependent effects. Altermagnets offer a potential solution that balances the two traditional magnet types.
Confirmation and Future Implications
Recent research has confirmed the existence of altermagnetism in diverse materials, challenging prior notions and opening new avenues for exploration. Beyond magnetism, altermagnetism may shed light on superconductivity, offering fundamental insights with broad scientific implications.
In conclusion, the discovery of altermagnetism highlights the complexity of magnetic phenomena and promises significant advancements in various fields, from electronics to materials science.
Read the original article on Nature.
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