Weyl magnons in breathing pyrochlore antiferromagnets
Fei-Ye Li1, Yao-Dong Li2, Yong Baek Kim3,4
1Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.
Nature Communications
|September 22, 2016
Summary
Researchers discovered Weyl magnons, topological excitations in frustrated quantum magnets. These novel excitations, analogous to Weyl fermions, exhibit unique surface states and can be manipulated with laboratory fields.
Area of Science:
- Condensed Matter Physics
- Quantum Magnetism
- Topological Materials
Background:
- Frustrated quantum magnets exhibit exotic ground states and unusual magnetic excitations.
- Topological excitations, like Weyl fermions in electronic systems, are of significant scientific interest.
Purpose of the Study:
- To investigate the presence of topological linear band crossings of magnons in antiferromagnets.
- To introduce and characterize 'Weyl magnons' in a physically relevant spin model.
Main Methods:
- Utilized a physically relevant spin model for a breathing pyrochlore lattice.
- Analyzed magnon band structures to identify topological features.
Main Results:
- Identified topological linear band crossings, termed Weyl magnons, in antiferromagnets.
- Demonstrated that bulk Weyl magnons imply chiral magnon surface states forming energy arcs.
- Showcased that these Weyl points can be manipulated in situ using applied fields.
Conclusions:
- Breathing pyrochlore antiferromagnets provide a unique platform for studying Weyl magnons.
- The findings suggest conditions for observing Weyl magnons and experimental probing methods.
- This work may prompt a re-examination of magnetic excitations in ordered magnetic systems.
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