Buckling-Mediated Phase Transitions in Nano-Electromechanical Phononic Waveguides
Buckling-Mediated Phase Transitions in Nano-Electromechanical Phononic Waveguides
复制标题
纳米机电声子波导中屈曲介导的相变
DOI：
10.1021/acs.nanolett.1c00764
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发表时间：
2021
期刊：
影响因子：
10.8
通讯作者：
Tawfick, Sameh
中科院分区：
文献类型：
--
作者：
Kim, SunPhil;Bunyan, Jonathan;Ferrari, Paolo F.;Kanj, Ali;Vakakis, Alexander F.;van der Zande, Arend M.;Tawfick, Sameh
用于在兆赫到千兆赫范围内传输机械信号的波导实现了片上声子电路，这带来了补充光子学和电子学的新功能。耦合纳米机电鼓头谐振器的晶格结构由于其高Q因子和精确设计的能带结构而适合于这些波导。在这里，我们证明了这种谐振器的热致弹性屈曲导致了波导中的相变，从而导致了对信号传输的可逆控制。具体地说，当冷却时，与主声模式相关联的最低频率传输频带消失。实验表明，上下带隙的合并，使得信号在激发边界处保持局域化。数值模拟表明，温度引起的通带破坏是非均匀弹性屈曲的结果，它扰乱了波导的周期性，抑制了波的传播。波导中的机械相变为芯片电路和计算中声子频带的剧烈重新配置提供了机会。
Waveguides for mechanical signal transmission in the megahertz to gigahertz regimes enable on-chip phononic circuitry, which brings new capabilities complementing photonics and electronics. Lattices of coupled nano-electromechanical drumhead resonators are suitable for these waveguides due to their high Q-factor and precisely engineered band structure. Here, we show that thermally induced elastic buckling of such resonators causes a phase transition in the waveguide leading to reversible control of signal transmission. Specifically, when cooled, the lowest-frequency transmission band associated with the primary acoustic mode vanishes. Experiments show the merging of the lower and upper band gaps, such that signals remain localized at the excitation boundary. Numerical simulations show that the temperature-induced destruction of the pass band is a result of inhomogeneous elastic buckling, which disturbs the waveguide’s periodicity and suppresses the wave propagation. Mechanical phase transitions in waveguides open opportunities for drastic phononic band reconfiguration in on-chip circuitry and computing.