A nanoscale phononic crystal filter (reflector) is designed for a kinetic inductance detector where the reflection band is matched to the quasiparticle recombination phonons with the aim to increase quasiparticle lifetime in the superconducting resonator. The inductor is enclosed by a 1-μm-wide phononic crystal membrane section with two simple hole patterns that each contain a partial spectral gap for various high-frequency phonon modes. The phononic crystal is narrow enough for low-frequency thermal phonons to propagate unimpeded. With 3D phonon scattering simulation over a 40 dB attenuation in transmitted power is found for the crystal, which is estimated to give a lifetime enhancement of nearly two orders of magnitude.

中文翻译：

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用于增强动感探测器准粒子寿命的复合声子晶体设计

纳米级声子晶体滤波器（反射器）设计用于动态电感检测器，其中反射带与准粒子复合声子匹配，目的是增加超导谐振器中的准粒子寿命。电感器被 1 μm 宽的声子晶体膜部分包围，该部分具有两个简单的孔图案，每个孔图案都包含用于各种高频声子模式的部分光谱间隙。声子晶体足够窄，低频热声子可以畅通无阻地传播。通过 3D 声子散射模拟，发现晶体的传输功率衰减超过 40 dB，据估计，这可使寿命提高近两个数量级。