论文标题
在低温温度下影响尼橙酸锂的损失通道
Loss channels affecting lithium niobate phononic crystal resonators at cryogenic temperature
论文作者
论文摘要
我们研究了在薄膜锂锂锂与超导量子电路中整合的微波频率音响晶体谐振器的性能。对于Millikelvin温度下的不同设计几何形状，我们实现了机械的内部质量因子$ q_i $以上$ 10^5-10^6 $在High Microwave Drive功率上，对应于谐振器内的$ 5 \ times10^6 $声子。通过用相同的镜像细胞设计扫描谐振器的缺陷尺寸，我们可以通过谐振器的内部质量因子间接观察完整的Phononic band -Bandgap的签名。质量因素的温度依赖性检查表明超导和两级系统（TLS）损失通道如何影响设备的性能。最后，我们观察到与谐振TLS衰减一致的异常低温频移，发现物质选择可以帮助减轻这些损失。
We investigate the performance of microwave-frequency phononic crystal resonators fabricated on thin-film lithium niobate for integration with superconducting quantum circuits. For different design geometries at millikelvin temperatures, we achieve mechanical internal quality factors $Q_i$ above $10^5 - 10^6$ at high microwave drive power, corresponding to $5\times10^6$ phonons inside the resonator. By sweeping the defect size of resonators with identical mirror cell designs, we are able to indirectly observe signatures of the complete phononic bandgap via the resonators' internal quality factors. Examination of quality factors' temperature dependence shows how superconducting and two-level system (TLS) loss channels impact device performance. Finally, we observe an anomalous low-temperature frequency shift consistent with resonant TLS decay and find that material choice can help to mitigate these losses.
