Page 22 - 《应用声学》2025年第2期
P. 22
282 2025 年 3 月
C 和域 D 的顶部棱可以支持拓扑棱态的传播,可以 [5] Ding Y, Peng Y, Zhu Y, et al. Experimental demonstra-
看到声波在域 C 和域 D 的底部棱上快速衰减,在大 tion of acoustic chern insulators[J]. Physical Review Let-
ters, 2019, 122(1): 014302.
约两个周期单位长度后就已无法继续传播,因此也
[6] Yang L, Wang Y, Meng Y, et al. Observation of dirac
无法激发出中央棱态模式以及后续域 A 和域 B 中 hierarchy in three-dimensional acoustic topological insu-
的棱态模式,结构整体表现出声学绝缘的特征。对 lators[J]. Physical Review Letters, 2022, 129(12): 125502.
[7] Shen Y X, Peng Y G, Zhao D G, et al. One-way local-
于图 4(d),由于存在域 A 和域 B 底部支持的棱态模
ized adiabatic passage in an acoustic system[J]. Physical
式与入射波矢之间的失配,同样导致了类似的声学 Review Letters, 2019, 122(9): 094501.
绝缘现象。结合图 4(a)∼(d) 来看,本文成功地在同 [8] Chen Z, Peng Y, Li H, et al. Efficient nonreciprocal mode
一个结构中实现了高阶棱态 -棱态在 3 个独立方向 transitions in spatiotemporally modulated acoustic meta-
materials[J]. Science Advances, 2021, 7(45): eabj1198.
之间的选择性拓扑传输。 [9] He H, Qiu C, Ye L, et al. Topological negative refraction
of surface acoustic waves in a Weyl phononic crystal[J].
5 结论 Nature, 2018, 560(7716): 61–64.
[10] Xu C, Ma G, Chen Z G, et al. Three-dimensional acous-
本文基于双层六角的人工声学晶格,成功在三 tic double-zero-index medium with a fourfold degenerate
dirac-like point[J]. Physical Review Letters, 2020, 124(7):
维空间中实现了高阶棱态 -棱态之间的选择性拓扑
074501.
输运。通过计算弯曲威尔逊循环以及微扰哈密顿量 [11] Zhang Z, Gao P, Liu W, et al. Structured sonic tube
的推导,证明了棱态之间的拓扑输运现象起源于结 with carbon nanotube-like topological edge states[J]. Na-
构中的拓扑阻碍相和 Jackiw-Rebbi 机制的协同作 ture Communications, 2022, 13(1): 5096.
[12] Benalcazar W A, Bernevig B A, Hughes T L. Electric mul-
用;通过边缘投影能带的计算,发现具有不同结构 tipole moments, topological multipole moment pumping,
的参数的域可以实现具有相反群速度的棱态模式。 and chiral hinge states in crystalline insulators[J]. Physi-
相应的声学有限元仿真结果表明,声波能够局域在 cal Review B, 2017, 96(24): 245115.
[13] Zheng L Y, Christensen J. Dirac hierarchy in acoustic
不同域之间的分界棱上,并且几乎没有反射地绕过
topological insulators[J]. Physical Review Letters, 2021,
结构的弯曲角,通过结构的中央棱在结构的顶部与 127(15): 156401.
底部之间传输。当改变入射波的方向时,棱态表现 [14] He C, Lai H S, He B, et al. Acoustic analogues of three-
dimensional topological insulators[J]. Nature Communi-
出被选择性激发的特性。考虑到本文所提出结构中
cations, 2020, 11(1): 2318.
存在的拓扑阻碍相,可以进一步将声学软边界纳入 [15] Wei Q, Zhang X, Deng W, et al. 3D hinge transport
结构的调控中,以实现更丰富的声波输运现象。此 in acoustic higher-order topological insulators[J]. Physi-
外,鉴于当前 3D 打印等工业技术已经较为成熟,可 cal Review Letters, 2021, 127(25): 255501.
[16] Xia C H, Lai H S, Sun X C, et al. Experimental
以方便地制备人工声学晶格进行相关实验研究。本 demonstration of bulk-hinge correspondence in a three-
文的研究有望应用于新型声学通信器件、减振降噪 dimensional topological dirac acoustic crystal[J]. Physical
设备的设计中。 Review Letters, 2022, 128(11): 115701.
[17] Wei Q, Zhang X, Deng W, et al. Higher-order topological
semimetal in acoustic crystals[J]. Nature Materials, 2021,
20(6): 812–817.
参 考 文 献
[18] Khanikaev A B, Fleury R, Mousavi S H, et al. Topologi-
cally robust sound propagation in an angular-momentum-
[1] Qi X L, Zhang S C. Topological insulators and super- biased graphene-like resonator lattice[J]. Nature Commu-
conductors[J]. Reviews of Modern Physics, 2011, 83(4): nications, 2015, 6(1): 8260.
1057–1110. [19] Po H C, Watanabe H, Vishwanath A. Fragile topology and
[2] Bansil A, Lin H, Das T. Colloquium: Topological wannier obstructions[J]. Physical Review Letters, 2018,
band theory[J]. Reviews of Modern Physics, 2016, 88(2): 121(12): 126402.
021004. [20] Song Z D, Elcoro L, Bernevig B A. Twisted bulk-
[3] Hu B, Zhang Z, Zhang H, et al. Non-Hermitian topo- boundary correspondence of fragile topology[J]. Science,
logical whispering gallery[J]. Nature, 2021, 597(7878): 2020, 367(6479): 794–797.
655–659. [21] Bradlyn B, Wang Z, Cano J, et al. Disconnected elemen-
[4] Hu B, Zhang Z, Yue Z, et al. Anti-parity-time symmetry tary band representations, fragile topology, and Wilson
in a su-schrieffer-heeger sonic lattice[J]. Physical Review loops as topological indices: An example on the triangu-
Letters, 2023, 131(6): 066601. lar lattice[J]. Physical Review B, 2019, 99(4): 045140.