Boundary-Induced Helical Bulk Acoustic Transport in LiNbO 3 Thin Films

Physical Review Letters 2026 Open access

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Authors: Zhe Li, Zhen-Hui Qin, Shu-Mao Wu, Chen-Bei Hao, F. M. Pan, Hao Yan, Yi‐Han He, Yan-Chen Zhou, Xuejun Yan, Si‐Yuan Yu, Chunying He, Ming-Hui Lu
+1 more Yan-Feng Chen
DOI: 10.1103/x6mm-jgzx
Cited by: 1
References: 59

Abstract

We experimentally demonstrate boundary-induced helical bulk states (BI-HBSs) for rf acoustic transport in LiNbO3 thin-film phononic crystals (∼175-200 MHz). A boundary-symmetry selection rule at an accidental Γ-point fourfold degeneracy creates interior bulk channels that couple to wide-aperture interdigital transducers without edge-aperture mismatch. Near-field vibrometry and two-port rf S parameters confirm low-loss propagation with strongly suppressed backscattering through wavelength-scale defects. The helical band also provides slow-wave, low-dispersion delay and phase control on chip.

Fields of Study & Subjects

Acoustic Wave Phenomena Research Geophysical Methods and Applications Speech and Audio Processing

Publication details

Journal / source
Physical Review Letters
Publisher
American Physical Society (APS)
Volume
136
Issue
20
Pages
207001–207001
Publication date
23 April 2026
Language
EN