Artificial gauge field modulated on-chip gigahertz acoustic coupling

Phononic integrated circuits (PhICs) represent a promising paradigm for on-chip acoustic information processing. However, conventional straight-waveguide architectures suffer from intrinsically dispersive inter-waveguide coupling, limiting bandwidth and fabrication tolerance. Meanwhile, evanescent crosstalk between adjacent waveguides fundamentally constrains integration density. Here, we introduce an artificial gauge field (AGF) to suppress inter-waveguide coupling dispersion on a CMOS-compatible GaN-on-4H-SiC platform, as validated by the theoretical and experimental demonstration of a broadband 1:1 power divider (PD). Beyond outperforming conventional straight-waveguide directional couplers in broadband performance, the AGF-modulated PD exhibits enhanced robustness against both global offsets and local waveguide-gap perturbations. We further demonstrate the first realization of acoustic coherent destruction of tunneling, enabling crosstalk-free parallel waveguide arrays for densely integrated phononic architectures. Our work thus marks a significant advance toward scalable, high-density, and fabrication-tolerant PhICs.