Chiral switching of elastic spin via dynamic encirclement of exceptional points

2026/07/10 by Chenwen Yang, Shubo Wang · 1 voice
Physics and Astronomy · #physics.class-ph

paper · pdf

Abstract

Dynamically encircling exceptional points (EPs) enables chiral state conversion in classical wave systems. However, whether this mechanism can be extended to chiral spin conversion has remained elusive. Here we demonstrate chiral switching of elastic spin via dynamic encirclement of EPs in a non-Hermitian micropolar (Cosserat) metamaterial. The interplay between micropolar chirality and anisotropic loss generates EPs with a nontrivial Riemann-sheet topology. Encircling these EPs converts the elastic spin, with the final spin sign dictated solely by the handedness of the encircling trajectory. Our results establish a fundamental route for the selective manipulation of elastic spin, opening avenues for non-Hermitian spin phononics and broader applications in other wave systems.

Citations

• Ultra-low damping of the translational motion of a composite graphite particle in a magneto-gravitational trap
• Perspective on Non-Hermitian Elastodynamics
• Hybrid Spin and Anomalous Spin-Momentum Locking in Surface Elastic Waves
• Winding around Non-Hermitian Singularities: General Theory and Topological Features
• Dynamically encircling exceptional points: in situ control of encircling loops and the role of the starting point
• Dynamically encircling exceptional points: Exact evolution and polarization state conversion
• Dynamically encircling exceptional points in a waveguide: asymmetric mode switching from the breakdown of adiabaticity
• Topological energy transfer in an optomechanical system with exceptional points
• Observation of non-Hermitian degeneracies in a chaotic exciton-polariton billiard
• Lateral Optical Force On Chiral Particles Near a Surface
• Chiral effect in plane isotropic micropolar elasticity and its application to chiral lattices
• Unidirectional Invisibility induced by PT-Symmetric Periodic Structures
• Making sense of non-Hermitian Hamiltonians
• PT-symmetric quantum mechanics
• PT-Symmetric Quantum Mechanics

Discussions

• Chenwen Yang, Shubo Wang: Chiral switching of elastic spin via dynamic encirclement of exceptional points https://arxiv.org/abs/2607.09083 https://arxiv.org/pdf/2607.09083 https://arxiv.org/html/2607. [bsky, 0 points, 0 comments]

Related

• Exceptional points in classical spin dynamics
• Spontaneous spin-selective structural phase transition in chiral crystals
• Dynamically encircling exceptional points: in situ control of encircling loops and the role of the starting point
• Polarization State Conversion through Chiral Butterfly Meta-Structure
• Symmetry requirements for current-induced spin magnetization specific to chiral crystals: Multipole analysis and the hidden spin glide symmetry