Inverse Chiral Phonon Zeeman Effect in Noncentrosymmetric Crystals

Abstract

We present a microscopic theory of the inverse chiral phonon Zeeman effect in noncentrosymmetric crystals. Within micropolar elasticity, coupled translational displacements and microrotations give rise to intrinsically chiral phonons, which generate an elliptically polarized internal magnetic field through dynamical piezoelectricity. In the high-frequency Floquet regime and under incomplete electronic screening, this field acts as an effective longitudinal Zeeman field on electronic spins, leading to spin polarization and band splitting. The results establish a purely lattice-driven mechanism for the inverse chiral phonon Zeeman effect in noncentrosymmetric crystals.

Figures (2)

• Figure 1: (Color online) Schematic illustration of (a) a chiral elastic wave in a continuum description, (b) independent translational and rotational degrees of freedom of rigid blocks, which constitute the basic viewpoint of micropolar elasticity, and (c) an effective longitudinal magnetic field induced by lifting the degeneracy of counter-rotating piezoelectric waves.
• Figure 2: (Color online) Calculated single-phonon magnetic-field amplitudes $B_{\pm}^{(1)}(q)$ as a function of phonon wave number $q$. Material parameters are taken from Ref. Kishine2020; see text for details.