论文标题
在tio $ _ {2} $中孔薄膜中探测Gigahertz连贯的声音声子
Probing Gigahertz Coherent Acoustic Phonons in TiO$_{2}$ Mesoporous Thin Films
论文作者
论文摘要
超高频率的声音谐音谐振器通常需要原子平坦的界面，以避免使用声子散射和脱落，从而导致昂贵的制造过程，例如分子束外交。相比之下，介孔薄膜基于廉价的湿化学制造技术。在这里，我们报告了介孔二氧化钛基的声学谐振器，共鸣高达90 GHz，质量因子从3到7。数值模拟显示与Picsecond Ultrasonics实验良好一致。我们还数字研究了声音速度变化对谐振器性能的影响。这种变化可以通过液体浸润到中孔中引起。我们的发现构成了基于介孔薄膜的构建基块工程的第一步，用于可重构光声传感器。
Ultrahigh-frequency acoustic-phonon resonators usually require atomically flat interfaces to avoid phonon scattering and dephasing, leading to expensive fabrication processes, such as molecular beam epitaxy. In contrast, mesoporous thin films are based on inexpensive wet chemical fabrication techniques. Here, we report mesoporous titanium dioxide-based acoustic resonators with resonances up to 90 GHz, and quality factors from 3 to 7. Numerical simulations show a good agreement with the picosecond ultrasonics experiments. We also numerically study the effect of changes in the speed of sound on the performance of the resonator. This change could be induced by liquid infiltration into the mesopores. Our findings constitute the first step towards the engineering of building blocks based on mesoporous thin films for reconfigurable optoacoustic sensors.
