Develop lattice-dynamics theory with external magnetic field for chiral crystals

Develop detailed lattice-dynamics calculations that include an external magnetic field for α-quartz and related chiral crystals, in order to achieve quantitative agreement with the observed acoustic magneto-chiral anisotropy, including the opposite signs for longitudinal and transverse modes.

Background

The authors observe that their macroscopic model matches magnitudes and frequency trends of aMChA but fails to reproduce the opposite sign observed between longitudinal and transverse waves for a given crystal handedness.

They attribute this discrepancy to assumptions in their model and suggest that a more rigorous approach—detailed lattice dynamics calculations that explicitly include an external magnetic field—should yield better agreement, noting that such calculations appear to be unavailable.

References

Better agreement can be expected from detailed lattice dynamics calculations including an external magnetic field, something that does not yet seem to exist.

— Observation of acoustic magneto-chiral anisotropy in $α$-quartz  (2604.01013 - Altangerel et al., 1 Apr 2026) in Main text, discussion of sign discrepancy between longitudinal and transverse aMChA (near the end of the paper)