Altermagnet

Source: PIB

Context: Scientists at the S.N. Bose National Centre for Basic Sciences have discovered a rare direction-dependent conduction polarity (DDCP) in Chromium Antimonide (CrSb), a newly discovered altermagnet.

• This is the first known altermagnet to show both p-type and n-type conduction within a single crystal based on direction

About Altermagnet:

• What are Altermagnets?

• Altermagnets are a novel class of magnetic materials that combine the internal spin ordering of antiferromagnets with the functional advantages of ferromagnets, yet exhibit zero net magnetization externally. Their hidden magnetic symmetry enables unique control over electron spin and transport without external magnetic signatures.

• Their hidden magnetic symmetry enables unique control over electron spin and transport without external magnetic signatures.

• Discovered By: This specific behaviour in CrSb was discovered by N. Bose National Centre for Basic Sciences, under the Department of Science and Technology, Government of India.

• Key Characteristics:

• Zero Net Magnetism: Despite magnetic ordering, they show no external magnetic field like regular magnets. High Spin Splitting: Internal electron spin energy levels differ greatly—30× room temperature in CrSb. High Thermal Stability: CrSb remains magnetic at temperatures twice that of room temperature, making it viable for industrial electronics. DDCP (Direction-Dependent Conduction Polarity): CrSb shows n-type behaviour along layers and p-type behaviour across layers, a first among known magnetic materials. Single-Crystalline Purity: High-quality crystals allow precise measurement of anisotropic conduction.

• Zero Net Magnetism: Despite magnetic ordering, they show no external magnetic field like regular magnets.

• High Spin Splitting: Internal electron spin energy levels differ greatly—30× room temperature in CrSb.

• High Thermal Stability: CrSb remains magnetic at temperatures twice that of room temperature, making it viable for industrial electronics.

• DDCP (Direction-Dependent Conduction Polarity): CrSb shows n-type behaviour along layers and p-type behaviour across layers, a first among known magnetic materials.

• Single-Crystalline Purity: High-quality crystals allow precise measurement of anisotropic conduction.

• How it Happens?

• In CrSb, when electric current flows within the crystal layers, electrons carry charge (n-type). When current flows across the layers, holes (absence of electrons) take over (p-type). This unusual conduction behaviour arises from asymmetric spin and charge distribution in the crystal structure.

• In CrSb, when electric current flows within the crystal layers, electrons carry charge (n-type).

• When current flows across the layers, holes (absence of electrons) take over (p-type).

• This unusual conduction behaviour arises from asymmetric spin and charge distribution in the crystal structure.

• Applications:

• Spintronics: Enables manipulation of electron spin rather than charge, paving the way for ultra-fast, low-energy memory devices. Compact Electronics: Acts as both p-type and n-type, removing the need for separate materials or doping. Thermoelectric: Enhances energy efficiency in power conversion systems. Simplified Manufacturing: Obviates heterostructures or junctions, reducing cost and complexity. Sustainable Tech: CrSb is non-toxic and earth-abundant, aligning with green electronics initiatives.

• Spintronics: Enables manipulation of electron spin rather than charge, paving the way for ultra-fast, low-energy memory devices.

• Compact Electronics: Acts as both p-type and n-type, removing the need for separate materials or doping.

• Thermoelectric: Enhances energy efficiency in power conversion systems.

• Simplified Manufacturing: Obviates heterostructures or junctions, reducing cost and complexity.

• Sustainable Tech: CrSb is non-toxic and earth-abundant, aligning with green electronics initiatives.