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Observation of Switchable Chiral Magnons in an Altermagnet
Zheyuan Liu1, Hodaka Kikuchi1,2, Zijun Wei1
1The University of Tokyo, Institute for Solid State Physics, Kashiwa 277-8581, Japan.
Physical Review Letters
|June 26, 2026
Summary
Researchers observed chiral magnons in altermagnets, which are spin waves that carry spin without energy loss. This discovery in manganese telluride (MnTe) opens new avenues for spintronic devices.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Mechanics
Background:
- Chiral magnons are quantized spin waves with chirality, enabling spin-angular momentum transport without energy loss.
- Altermagnets, materials with alternating magnetic sublattices but no net magnetization, are predicted to host chiral magnons.
- These materials offer a stray-field-free platform for manipulating spin currents, crucial for spintronics.
Purpose of the Study:
- To directly observe chiral magnons in an altermagnetic material.
- To investigate the control and manipulation of magnon chirality in altermagnets.
Main Methods:
- Polarized inelastic neutron scattering was employed to detect and characterize magnon excitations.
- Magnetic field control was utilized to investigate the switching of magnon chirality.
Main Results:
- Direct observation of chiral magnons in the altermagnetic prototype manganese telluride (MnTe).
- Demonstration of reversible switching of magnon chirality by applying an external magnetic field.
Conclusions:
- The findings provide direct experimental evidence for chiral magnons in altermagnets.
- The ability to control magnon chirality establishes a foundation for developing functional altermagnetic magnonic devices.
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