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Highly dispersive scattering from defects in noncollinear magnets
Wolfram Brenig1, A L Chernyshev2
1Institut für Theoretische Physik, Technische Universität Braunschweig, 38106 Braunschweig, Germany.
Physical Review Letters
|August 29, 2014
Summary
Pointlike defects in noncollinear magnets cause dispersive magnon scattering, challenging previous assumptions. This arises from umklapp scattering off impurity-induced spin textures in these magnetic systems.
Area of Science:
- Condensed Matter Physics
- Magnetism and Spintronics
- Quantum Materials
Background:
- Magnon scattering typically assumes momentum independence in defect interactions.
- Noncollinear magnets exhibit complex magnetic ordering and spin textures.
Purpose of the Study:
- To investigate the impact of pointlike defects on magnon scattering in noncollinear magnets.
- To challenge the conventional understanding of momentum independence in defect-mediated scattering.
Main Methods:
- Numerical linear spin-wave theory.
- Calculation of the T matrix and resolvent.
- Analysis of impurity-induced spin texture.
Main Results:
- Discovered a highly dispersive structure in magnon scattering due to pointlike defects.
- Momentum dependence of scattering is governed by magnon dispersion and ordering vector.
- Identified umklapp scattering as the mechanism behind this phenomenon.
Conclusions:
- Pointlike defects in noncollinear magnets introduce momentum-dependent magnon scattering.
- This finding necessitates a revision of standard paradigms in condensed matter physics.
- The study highlights the importance of considering noncollinear ground states in defect scattering phenomena.
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