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High Resolution Phonon-assisted Quasi-resonance Fluorescence Spectroscopy
Published on: June 28, 2016
Band transition and topological interface modes in 1D elastic phononic crystals
Jianfei Yin1, Massimo Ruzzene2,3, Jihong Wen4
1Laboratory of Science and Technology on Integrated Logistics Support, National University of Defense Technology, Changsha, Hunan, 410073, P.R. China. nmhsyjf@nudt.edu.cn.
Abstract:
In this report, we design a one-dimensional elastic phononic crystal (PC) comprised of an Aluminum beam with periodically arranged cross-sections to study the inversion of bulk bands due to the change of topological phases. As the geometric parameters of the unit cell varies, the second bulk band closes and reopens forming a topological transition point. This phenomenon is confirmed for both longitudinal waves and bending waves. By constructing a structural system formed by two PCs with different topological phases, for the first time, we experimentally demonstrate the existence of interface mode within the bulk band gap as a result of topological transition for both longitudinal and bending modes in elastic systems, although for bending modes, additional conditions have to be met in order to have the interface mode due to the dispersive nature of the bending waves in uniform media compared to the longitudinal waves.
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