Deployable Nanoelectromechanical Bound States in the Continuum Enabled by GHz Lamb Wave Phononic Crystals on LiNbO3 Thin Films

Hua-Yang Chen; Sheng-Nan Liang; Shu-Mao Wu; Si-Yuan Yu; Yan-Feng Chen; Zhen-hui Qin

arxiv: 2502.18375 · v1 · submitted 2025-02-25 · ⚛️ physics.app-ph · cond-mat.mes-hall· cond-mat.mtrl-sci

Deployable Nanoelectromechanical Bound States in the Continuum Enabled by GHz Lamb Wave Phononic Crystals on LiNbO3 Thin Films

Sheng-Nan Liang , Zhen-hui Qin , Shu-Mao Wu , Hua-Yang Chen , Si-Yuan Yu , Yan-Feng Chen This is my paper

Pith reviewed 2026-05-23 02:36 UTC · model grok-4.3

classification ⚛️ physics.app-ph cond-mat.mes-hallcond-mat.mtrl-sci

keywords bound states in the continuumquasi-BICsLamb wavesphononic crystalslithium niobatenanoelectromechanical systemsgigahertz frequenciesmirror symmetry breaking

0 comments

The pith

Controlled mirror symmetry breaking in LiNbO3 Lamb wave phononic crystals produces quasi-BICs excitable by traveling waves.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper establishes that decoupling symmetric and antisymmetric Lamb wave modes in suspended LiNbO3 thin films creates a stable base for bound states in the continuum. Controlled breaking of mirror symmetry then couples these modes in a targeted way, yielding quasi-BICs that keep high quality factors while becoming excitable by ordinary traveling waves. This removes the need for special excitation setups and allows multiple such resonators to be placed along one transmission line at distinct frequencies and locations. A sympathetic reader would care because the approach turns a symmetry-constrained theoretical concept into a scalable, on-chip nanoelectromechanical platform for signal processing and sensing.

Core claim

Decoupling of symmetric (S) and antisymmetric (A) Lamb wave modes supplies a robust framework for BICs on LiNbO3 thin films. Controlled mirror symmetry breaking then induces targeted coupling between the S and A modes, producing quasi-BICs that retain high-Q characteristics, can be excited by traveling waves, and support multiplexing of resonators along a single transmission line at unique frequencies and spatial positions.

What carries the argument

Decoupling of symmetric (S) and antisymmetric (A) Lamb wave modes combined with controlled mirror symmetry breaking in GHz nanoscale phononic crystals on LiNbO3 films.

If this is right

Quasi-BICs become excitable by standard traveling waves without specialized schemes.
Multiple quasi-BIC resonators can be multiplexed along one transmission line at distinct frequencies and positions.
The method supplies a scalable route for on-chip integration of BICs in nanoelectromechanical devices.
New possibilities open for advanced signal processing, high-precision sensing, and quantum acoustics.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

The same symmetry-breaking approach could be tested on other thin-film piezoelectrics to check transferability beyond LiNbO3.
Arrays of frequency-addressable quasi-BIC sensors might be integrated directly with existing RF circuitry on one chip.
If the preserved Q remains high enough at scale, the platform could support coherent phonon interactions relevant to quantum acoustics experiments.

Load-bearing premise

The decoupling of symmetric and antisymmetric Lamb wave modes remains a stable foundation even after the controlled symmetry breaking required to make quasi-BICs usable.

What would settle it

Observation that controlled mirror symmetry breaking either fails to couple S and A modes while preserving high Q or produces modes that cannot be excited by traveling waves along a single transmission line.

read the original abstract

Bound states in the continuum (BICs) are a fascinating class of eigenstates that trap energy within the continuum, enabling breakthroughs in ultra-low-threshold lasing, high-Q sensing, and advanced wave-matter interactions. However, their stringent symmetry requirements hinder practical integration, especially in acoustic and electromechanical systems where efficient mode excitation is challenging. Here, we demonstrate deployable nanoelectromechanical quasi-BICs on suspended lithium niobate (LiNbO3) thin films, enabled by nanoscale Lamb wave phononic crystals (PnCs) operating at gigahertz frequencies. By exploiting the decoupling of symmetric (S) and antisymmetric (A) Lamb wave modes, we create a robust framework for BICs. Controlled mirror symmetry breaking induces targeted coupling between the S and A modes, resulting in quasi-BICs that preserve high-Q characteristics and can be excited by traveling waves, eliminating the need for specialized excitation schemes. Our approach enables the multiplexing of quasi-BIC resonators along a single transmission line, each corresponding to a unique frequency and spatial position. This work presents a scalable route for the on-chip integration of BICs, bridging the gap between theoretical concepts and practical nanoelectromechanical devices, and opening new avenues in advanced signal processing, high-precision sensing, and quantum acoustics.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Desk Editor's Note private letter to a colleague

The paper describes a framework for quasi-BICs in GHz Lamb-wave PnCs on suspended LiNbO3 that uses S/A mode decoupling plus controlled symmetry breaking to allow traveling-wave excitation and single-line multiplexing.

read the letter

The main thing to know is that this work claims a practical path to high-Q quasi-BICs in nanoelectromechanical devices by first decoupling symmetric and antisymmetric Lamb modes in phononic crystals on thin LiNbO3, then applying targeted mirror symmetry breaking to produce usable quasi-BICs that traveling waves can drive directly, plus the ability to multiplex several at different frequencies along one line. That combination on suspended films at gigahertz frequencies is the concrete step they highlight for integration into sensing or signal processing hardware. The abstract presents the decoupling as supplying a protected base and the symmetry break as selective enough to keep the high-Q property intact while removing the need for special excitation. The construction reads as internally consistent with no obvious contradictions in the stated steps. What the paper does well is spell out an engineering route that directly tackles the integration barrier for BICs in these platforms. The soft spot is the complete absence of data, methods, or numbers in what we have. Without measured Q values, simulation details, or fabrication tolerances, it is impossible to check whether the high-Q preservation actually occurs once the symmetry is broken or whether the mode coupling stays as selective as claimed. The central assumption that the initial decoupling survives the controlled breaking in a usable way therefore remains untested here. This is for people working on phononic crystals, nanoelectromechanical resonators, or acoustic quantum devices who need concrete integration ideas. A reader focused on practical BIC implementations would get value from the proposed framework. It deserves peer review because the logic is coherent and the application target is clear, even if the results will need substantial verification.

Referee Report

0 major / 2 minor

Summary. The manuscript reports the demonstration of deployable nanoelectromechanical quasi-bound states in the continuum (quasi-BICs) enabled by gigahertz Lamb wave phononic crystals on suspended lithium niobate thin films. The approach relies on the decoupling of symmetric (S) and antisymmetric (A) Lamb wave modes to establish a BIC framework, followed by controlled mirror symmetry breaking to induce targeted S-A coupling, resulting in quasi-BICs that maintain high quality factors and can be excited by traveling waves. This enables multiplexing of quasi-BIC resonators along a single transmission line at unique frequencies and positions.

Significance. If the experimental results and theoretical framework hold, this work represents a significant step toward practical on-chip integration of BICs in nanoelectromechanical systems. The ability to use traveling-wave excitation and multiplex resonators addresses key challenges in the field, potentially enabling new applications in high-precision sensing, advanced signal processing, and quantum acoustics. The paper provides an experimental demonstration rather than a re-derivation, which strengthens its contribution. The stress-test concern regarding whether the S-A decoupling framework remains intact under controlled symmetry breaking does not appear to introduce an internal inconsistency based on the presented construction.

minor comments (2)

[Abstract] Abstract: the term 'deployable' is introduced without definition; a short clarification of its meaning in the context of the device architecture would improve accessibility.
The manuscript would benefit from an explicit statement of the measured Q-factors for the quasi-BICs versus the unperturbed BIC case to quantify the preservation claim.

Simulated Author's Rebuttal

0 responses · 0 unresolved

We thank the referee for the positive assessment of our work on deployable nanoelectromechanical quasi-BICs in GHz Lamb-wave PnCs on LiNbO3, including the recognition of the traveling-wave excitation and multiplexing capabilities. The recommendation for minor revision is noted. No specific major comments were provided in the report.

Circularity Check

0 steps flagged

No significant circularity identified

full rationale

The paper presents an experimental demonstration of deployable quasi-BICs on LiNbO3 thin films via GHz Lamb wave PnCs. The central construction relies on physical mode decoupling of S and A Lamb waves followed by controlled mirror symmetry breaking to enable targeted coupling and traveling-wave excitation. No equations, fitted parameters, or self-citations are shown that would reduce any claimed prediction or uniqueness result to the inputs by construction. The description frames the work as a scalable fabrication route rather than a re-derivation, rendering the derivation chain self-contained against external benchmarks.

Axiom & Free-Parameter Ledger

0 free parameters · 0 axioms · 0 invented entities

Abstract-only review supplies no explicit free parameters, axioms, or invented entities; none can be extracted.

pith-pipeline@v0.9.0 · 5794 in / 1164 out tokens · 21927 ms · 2026-05-23T02:36:11.853170+00:00 · methodology

discussion (0)

Reference graph

Works this paper leans on

32 extracted references · 32 canonical work pages

[1]

von Neumann and E

J . von Neumann and E. Wigner, Über merkwürdige diskrete Eigenwerte, Phys. Z. 30, 465–467 (in German) (1929)

work page 1929
[2]

C. W. Hsu, B. Zhen, A. D. Stone, J. D. Joannopoulos, and M. Soljačić, Bound states in the continuum, Nat. Rev. Mater. 1, 16048 (2016)

work page 2016
[3]

D. C. Marinica, A. G. Borisov, and S. V. Shabanov, Bound states in the continuum in photonics, Phys. Rev. Lett. 100, 183902 (2008)

work page 2008
[4]

Plotnik, O

Y. Plotnik, O. Peleg, F. Dreisow, M. Heinrich, S. Nolte, A. Szameit, and M. Segev, Experimental observation of optical bound states in the continuum, Phys. Rev. Lett. 107, 183901 (2011)

work page 2011
[5]

C. W. Hsu, B. Zhen, J. Lee, S. L. Chua, S. G. Johnson, J. D. Joannopoulos, and M. Soljačić, Observation of trapped light within the radiation continuum, Nature 499, 188–191 (2013)

work page 2013
[6]

B. Zhen, C. W. Hsu, L. Lu, A. D. Stone, and M. Soljačić, Topological nature of optical bound states in the continuum, Phys. Rev. Lett. 113, 257401 (2014)

work page 2014
[7]

Y. Yang, C. Peng, Y. Liang, Z. Li, and S. Noda, Analytical perspective for bound states in the continuum in photonic crystal slabs, Phys. Rev. Lett. 113, 037401 (2014)

work page 2014
[8]

Mukherjee, A

S. Mukherjee, A. Spracklen, D. Choudhury, N. Goldman, P. Ohberg, E. Andersson, and R. R. Thomson, Observation of a localized flat-band state in a photonic Lieb lattice, Phys. Rev. Lett. 114, 245504 (2015)

work page 2015
[9]

Kodigala, T

A. Kodigala, T. Lepetit, Q. Gu, B. Bahari, Y. Fainman, and B. Kanté, Lasing action from photonic bound states in the continuum, Nature 541, 196–199 (2017)

work page 2017
[10]

Gomis-Bresco, D

J. Gomis-Bresco, D. Artigas, and L. Torner, Anisotropy-induced photonic bound states in the continuum, Nat. Photonics 11, 232–236 (2017)

work page 2017
[11]

Z. Yu, X. Xi, J. Ma, H. K. Tsang, C.-L. Zou, and X. Sun, Photonic integrated circuits with bound states in the continuum, Optica 6, 1342–1348 (2019)

work page 2019
[12]

S. I. Azzam and A. V. Kildishev, Photonic bound states in the continuum: From basics to applications, Adv. Opt. Mater. 9, 2001469 (2021)

work page 2021
[13]

M. S. Hwang, H. C. Lee, K. H. Kim, K. Y. Jeong, S. H. Kwon, K. Koshelev, et al., Ultralow-threshold laser using super-bound states in the continuum, Nat. Commun. 12, 4135 (2021)

work page 2021
[14]

M. Kang, T. Liu, C. T. Chan, and M. Xiao, Applications of bound states in the continuum in photonics, Nat. 8 Rev. Phys. 5, 659–678 (2023)

work page 2023
[15]

Y. X. Xiao, G. Ma, Z. Q. Zhang, and C. T. Chan, Topological subspace-induced bound state in the continuum, Phys. Rev. Lett. 118, 166803 (2017)

work page 2017
[16]

Huang, T

S. Huang, T. Liu, Z. Zhou, X. Wang, J. Zhu, and Y. Li, Extreme sound confinement from quasibound states in the continuum, Phys. Rev. Appl. 14, 021001 (2020)

work page 2020
[17]

Huang, Y

L. Huang, Y. K. Chiang, S. Huang, C. Shen, F. Deng, Y. Cheng, B. Jia, Y. Li, D. A. Powell, and A. E. Miroshnichenko, Sound trapping in an open resonator, Nat. Commun. 12, 4819 (2021)

work page 2021
[18]

Z. Zhou, B. Jia, N. Wang, X. Wang, and Y. Li, Observation of perfectly-chiral exceptional point via bound state in the continuum, Phys. Rev. Lett. 130, 116101 (2023)

work page 2023
[19]

L. Liu, T. Li, Q. Zhang, M. Xiao, and C. Qiu, Universal mirror-stacking approach for constructing topological bound states in the continuum, Phys. Rev. Lett. 130, 106301 (2023)

work page 2023
[20]

Z. Pu, H. He, L. Luo, Q. Ma, L. Ye, M. Ke, and Z. Liu, Acoustic higher-order Weyl semimetal with bound hinge states in the continuum, Phys. Rev. Lett. 130, 116103 (2023)

work page 2023
[21]

Kronowetter, M

F. Kronowetter, M. Maeder, Y. K. Chiang, L. Huang, J. D. Schmid, S. Oberst, et al., Realistic prediction and engineering of high-Q modes to implement stable Fano resonances in acoustic devices, Nat. Commun. 14, 6847 (2023)

work page 2023
[22]

S. Yin, L. Ye, H. He, X. Huang, M. Ke, W. Deng, et al., Valley edge states as bound states in the continuum, Sci. Bull. 69, 123–130 (2024)

work page 2024
[23]

J. Guo, Z. Gu, and J. Zhu, Realization of Merged Topological Corner States in the Continuum in Acoustic Crystals, Phys. Rev. Lett. 133, 236603 (2024)

work page 2024
[24]

Farhat, Y

M. Farhat, Y. Achaoui, J. A. I. Martínez, M. Addouche, Y. Wu, and A. Khelif, Observation of ultra-high-Q resonators in the ultrasound via bound states in the continuum, Adv. Sci. 11, 2402917 (2024)

work page 2024
[25]

Y. Yang, H. Jia, Y. Yang, P. Zhou, and J. Yang, Observation of merged Fabry-Perot bound states in the continuum within an underwater phononic crystal, Phys. Rev. B 110, 184108 (2024)

work page 2024
[26]

A. G. Every and A. A. Maznev, Fano line shapes of leaky surface acoustic waves extending from supersonic surface wave points, Wave Motion 79, 1–9 (2018)

work page 2018
[27]

H. Tong, S. Liu, M. Zhao, and K. Fang, Observation of phonon trapping in the continuum with topological charges, Nat. Commun. 11, 5216 (2020)

work page 2020
[28]

S. Liu, H. Tong, and K. Fang, Optomechanical crystal with bound states in the continuum, Nat. Commun. 13, 3187 (2022)

work page 2022
[29]

Deriy, I

I. Deriy, I. Toftul, M. Petrov, and A. Bogdanov, Bound States in the Continuum in Compact Acoustic Resonators, Phys. Rev. Lett. 128, 084301 (2022)

work page 2022
[30]

S. An, T. Liu, L. Cao, Z. Gu, H. Fan, Y. Zeng, L. Cheng, J. Zhu, and B. Assouar, Bound States in the Continuum in Compact Acoustic Resonators, Phys. Rev. Lett. 132, 187202 (2024)

work page 2024
[31]

H. Tong, S. Liu, and K. Fang, Merging mechanical bound states in the continuum in high-aspect-ratio phononic, Commun. Phys. 7, 197 (2024)

work page 2024
[32]

J. L. Rose, Ultrasonic Guided Waves in Solid Media (Cambridge University Press, 2014). 9

work page 2014

[1] [1]

von Neumann and E

J . von Neumann and E. Wigner, Über merkwürdige diskrete Eigenwerte, Phys. Z. 30, 465–467 (in German) (1929)

work page 1929

[2] [2]

C. W. Hsu, B. Zhen, A. D. Stone, J. D. Joannopoulos, and M. Soljačić, Bound states in the continuum, Nat. Rev. Mater. 1, 16048 (2016)

work page 2016

[3] [3]

D. C. Marinica, A. G. Borisov, and S. V. Shabanov, Bound states in the continuum in photonics, Phys. Rev. Lett. 100, 183902 (2008)

work page 2008

[4] [4]

Plotnik, O

Y. Plotnik, O. Peleg, F. Dreisow, M. Heinrich, S. Nolte, A. Szameit, and M. Segev, Experimental observation of optical bound states in the continuum, Phys. Rev. Lett. 107, 183901 (2011)

work page 2011

[5] [5]

C. W. Hsu, B. Zhen, J. Lee, S. L. Chua, S. G. Johnson, J. D. Joannopoulos, and M. Soljačić, Observation of trapped light within the radiation continuum, Nature 499, 188–191 (2013)

work page 2013

[6] [6]

B. Zhen, C. W. Hsu, L. Lu, A. D. Stone, and M. Soljačić, Topological nature of optical bound states in the continuum, Phys. Rev. Lett. 113, 257401 (2014)

work page 2014

[7] [7]

Y. Yang, C. Peng, Y. Liang, Z. Li, and S. Noda, Analytical perspective for bound states in the continuum in photonic crystal slabs, Phys. Rev. Lett. 113, 037401 (2014)

work page 2014

[8] [8]

Mukherjee, A

S. Mukherjee, A. Spracklen, D. Choudhury, N. Goldman, P. Ohberg, E. Andersson, and R. R. Thomson, Observation of a localized flat-band state in a photonic Lieb lattice, Phys. Rev. Lett. 114, 245504 (2015)

work page 2015

[9] [9]

Kodigala, T

A. Kodigala, T. Lepetit, Q. Gu, B. Bahari, Y. Fainman, and B. Kanté, Lasing action from photonic bound states in the continuum, Nature 541, 196–199 (2017)

work page 2017

[10] [10]

Gomis-Bresco, D

J. Gomis-Bresco, D. Artigas, and L. Torner, Anisotropy-induced photonic bound states in the continuum, Nat. Photonics 11, 232–236 (2017)

work page 2017

[11] [11]

Z. Yu, X. Xi, J. Ma, H. K. Tsang, C.-L. Zou, and X. Sun, Photonic integrated circuits with bound states in the continuum, Optica 6, 1342–1348 (2019)

work page 2019

[12] [12]

S. I. Azzam and A. V. Kildishev, Photonic bound states in the continuum: From basics to applications, Adv. Opt. Mater. 9, 2001469 (2021)

work page 2021

[13] [13]

M. S. Hwang, H. C. Lee, K. H. Kim, K. Y. Jeong, S. H. Kwon, K. Koshelev, et al., Ultralow-threshold laser using super-bound states in the continuum, Nat. Commun. 12, 4135 (2021)

work page 2021

[14] [14]

M. Kang, T. Liu, C. T. Chan, and M. Xiao, Applications of bound states in the continuum in photonics, Nat. 8 Rev. Phys. 5, 659–678 (2023)

work page 2023

[15] [15]

Y. X. Xiao, G. Ma, Z. Q. Zhang, and C. T. Chan, Topological subspace-induced bound state in the continuum, Phys. Rev. Lett. 118, 166803 (2017)

work page 2017

[16] [16]

Huang, T

S. Huang, T. Liu, Z. Zhou, X. Wang, J. Zhu, and Y. Li, Extreme sound confinement from quasibound states in the continuum, Phys. Rev. Appl. 14, 021001 (2020)

work page 2020

[17] [17]

Huang, Y

L. Huang, Y. K. Chiang, S. Huang, C. Shen, F. Deng, Y. Cheng, B. Jia, Y. Li, D. A. Powell, and A. E. Miroshnichenko, Sound trapping in an open resonator, Nat. Commun. 12, 4819 (2021)

work page 2021

[18] [18]

Z. Zhou, B. Jia, N. Wang, X. Wang, and Y. Li, Observation of perfectly-chiral exceptional point via bound state in the continuum, Phys. Rev. Lett. 130, 116101 (2023)

work page 2023

[19] [19]

L. Liu, T. Li, Q. Zhang, M. Xiao, and C. Qiu, Universal mirror-stacking approach for constructing topological bound states in the continuum, Phys. Rev. Lett. 130, 106301 (2023)

work page 2023

[20] [20]

Z. Pu, H. He, L. Luo, Q. Ma, L. Ye, M. Ke, and Z. Liu, Acoustic higher-order Weyl semimetal with bound hinge states in the continuum, Phys. Rev. Lett. 130, 116103 (2023)

work page 2023

[21] [21]

Kronowetter, M

F. Kronowetter, M. Maeder, Y. K. Chiang, L. Huang, J. D. Schmid, S. Oberst, et al., Realistic prediction and engineering of high-Q modes to implement stable Fano resonances in acoustic devices, Nat. Commun. 14, 6847 (2023)

work page 2023

[22] [22]

S. Yin, L. Ye, H. He, X. Huang, M. Ke, W. Deng, et al., Valley edge states as bound states in the continuum, Sci. Bull. 69, 123–130 (2024)

work page 2024

[23] [23]

J. Guo, Z. Gu, and J. Zhu, Realization of Merged Topological Corner States in the Continuum in Acoustic Crystals, Phys. Rev. Lett. 133, 236603 (2024)

work page 2024

[24] [24]

Farhat, Y

M. Farhat, Y. Achaoui, J. A. I. Martínez, M. Addouche, Y. Wu, and A. Khelif, Observation of ultra-high-Q resonators in the ultrasound via bound states in the continuum, Adv. Sci. 11, 2402917 (2024)

work page 2024

[25] [25]

Y. Yang, H. Jia, Y. Yang, P. Zhou, and J. Yang, Observation of merged Fabry-Perot bound states in the continuum within an underwater phononic crystal, Phys. Rev. B 110, 184108 (2024)

work page 2024

[26] [26]

A. G. Every and A. A. Maznev, Fano line shapes of leaky surface acoustic waves extending from supersonic surface wave points, Wave Motion 79, 1–9 (2018)

work page 2018

[27] [27]

H. Tong, S. Liu, M. Zhao, and K. Fang, Observation of phonon trapping in the continuum with topological charges, Nat. Commun. 11, 5216 (2020)

work page 2020

[28] [28]

S. Liu, H. Tong, and K. Fang, Optomechanical crystal with bound states in the continuum, Nat. Commun. 13, 3187 (2022)

work page 2022

[29] [29]

Deriy, I

I. Deriy, I. Toftul, M. Petrov, and A. Bogdanov, Bound States in the Continuum in Compact Acoustic Resonators, Phys. Rev. Lett. 128, 084301 (2022)

work page 2022

[30] [30]

S. An, T. Liu, L. Cao, Z. Gu, H. Fan, Y. Zeng, L. Cheng, J. Zhu, and B. Assouar, Bound States in the Continuum in Compact Acoustic Resonators, Phys. Rev. Lett. 132, 187202 (2024)

work page 2024

[31] [31]

H. Tong, S. Liu, and K. Fang, Merging mechanical bound states in the continuum in high-aspect-ratio phononic, Commun. Phys. 7, 197 (2024)

work page 2024

[32] [32]

J. L. Rose, Ultrasonic Guided Waves in Solid Media (Cambridge University Press, 2014). 9

work page 2014