Orthogonal Magnon-Phonon Coupling Enables Information Encoding in Bulk CrSBr

Orthogonal magnon-phonon coupling in layered magnets provides a unique platform for energy-efficient wave-based information processing. In this study, we employ polarization-controlled ultrafast spectroscopy to investigate layered magnet CrSBr. We reveal the propagation of magnons along the b-axis (∼24 GHz) and coherent acoustic phonons (CAPs) along the a-axis (18.1 GHz). Magnons and CAPs are spatially separated by 80° and feature magnetic-field-tunable magnetoelastic coupling strengths of up to 1.5 GHz (at polarization 40°). The successful demonstration of polarization-multiplexed binary logic encoding, where a-axis polarization excites phonons for logic “0” and b-axis polarization activates magnons for logic “1”, validates the feasibility of this approach. The encoding and retrieval of alphabetic characters further confirm the practical applicability of the proposed system. This naturally orthogonal wave coupling in CrSBr establishes a foundation for wave-based logic devices. It promises significant applications in quantum information processing and computing technologies.