Altermagnets are novel antiferromagnetic materials enabling spin splitting without spin-orbit coupling or net magnetization. Offering long spin lifetimes and stability, they unlock new possibilities in spintronics and valleytronics. Applications include ultra-fast memory, energy-efficient computing, sensors, and quantum devices, marking a breakthrough in quantum materials and device engineering.
Copyright infringement not intended
Picture Courtesy: PHYS
Research on altermagnets led by Professor Liu Junwei from the Hong Kong University of Science and Technology (HKUST), published in Nature Physics, opens doors to next-gen spintronic and valleytronic devices.
Altermagnets are a class of antiferromagnetic materials that exhibit momentum-dependent spin splitting without requiring spin-orbit coupling (SOC) or net magnetization.
Unlike conventional magnetic materials, they maintain the stability of antiferromagnetic structures while allowing for long spin lifetimes.
Traditional approaches to generating spin polarization in materials involve:
Altermagnets, however, utilize a fundamentally different mechanism:
Spintronics Applications
Traditional spintronic devices use ferromagnets or SOC to manipulate electron spins. For example, magnetic tunnel junctions (MTJs) in hard drives rely on spin to read and write data.
Altermagnets offer a new way to create spin-polarized currents without SOC, making devices more robust and energy-efficient. They could lead to advanced spin valves, spin transistors, or even spin logic gates for next-generation computers.
Valleytronics Applications
Materials like MoS2 (molybdenum disulfide) are popular in valleytronics because they have multiple valleys where electrons can reside.
Altermagnets like Rb1-δV2Te2O take this further by locking spins to specific valleys, allowing scientists to control both spin and valley with simple methods like strain or electric currents. This could enable valleytronic transistors or valley-based memory devices.
Source:
|
PRACTICE QUESTION Q.In the question given below, there are two statements marked as Assertion (A) and Reason (R). Mark your answer as per the codes provided: Assertion (A) : Earth behaves like a giant magnet. Reason (R): The Earth’s magnetic field arises due to the movement of molten iron in the outer core. Which of the options given below is correct? A) Both A and R are true, and R is the correct explanation for A. B) Both A and R are true, but R is not the correct explanation for A. C) A is true, but R is false. D) A is false, but R is true. Answer: A Explanation: Assertion (A) is true: The Earth has a magnetic field with a North and South magnetic pole, similar to a bar magnet. This field is responsible for phenomena like the alignment of compass needles and the protection of Earth from harmful solar radiation. Reason (R) is true: The leading scientific theory for the Earth's magnetic field is called the dynamo theory. This theory proposes that the movement of electrically conductive fluids (molten iron) in the Earth's outer core, driven by convection currents and the Earth's rotation, generates electrical currents. These electrical currents, in turn, produce the Earth's magnetic field. The movement of molten iron in the Earth's outer core (Reason R) is the fundamental reason why the Earth behaves like a giant magnet (Assertion A). |
© 2025 iasgyan. All right reserved
