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Pseudo-Hermitian magnon dynamics
Xi-Guang Wang1, Jamal Berakdar2
1School of Physics, Central South University, Changsha 410083, People's Republic of China.
Summary
Pseudo-Hermitian physics, applied to magnetic materials, reveals unique behaviors in spin waves (magnons). This research explores phenomena like mode amplification and non-reciprocal propagation in open quantum systems.
Area of Science:
- Condensed Matter Physics
- Quantum Mechanics
- Materials Science
Background:
- Hermitian operators define closed quantum systems with real energy spectra.
- Pseudo-Hermitian (PT-symmetric) systems, a class of non-Hermitian systems, can describe open systems while retaining real energy spectra, though eigenmodes may not be orthogonal.
Purpose of the Study:
- To review recent advancements in pseudo-Hermitian physics applied to low-energy excitations in magnetically ordered materials.
- To focus on spin wave (magnon) excitations and their unique properties under pseudo-Hermiticity.
Main Methods:
- Review of theoretical and experimental progress in pseudo-Hermitian physics.
- Analysis of various magnetic systems: ferromagnetic, antiferromagnetic, magnonic crystals, and hybrid structures.
- Investigation of different environmental coupling and spatio-temporal engineering.
Main Results:
- Pseudo-Hermiticity introduces unique phenomena in magnons, including mode amplification and non-reciprocal propagation.
- Exploration of effects like the non-Hermitian skin effect, magnon cloaking, and PT-symmetric assisted Floquet engineering.
- Discussion of topological energy transfer and field-induced enhanced sensitivity in these systems.
Conclusions:
- Pseudo-Hermitian physics offers novel insights into the behavior of open quantum systems, particularly spin waves in magnetic materials.
- The unique properties arising from pseudo-Hermiticity open new avenues for controlling and manipulating magnonic excitations.
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