AI 中文总结
该研究开发了与高阻抗微波谐振器强耦合的无释放型铌酸锂声子晶体腔，实现了高机电耦合率与品质因子，为微波与声波的集成提供了新的紧凑可扩展接口，适用于传感等系统。
AI 中文摘要
声子在存储和传输量子信息方面具有应用前景，包括用于超导量子比特与光之间的机械介导量子互连。声子晶体腔可将千兆赫兹声波限制在微米级体积内，该体积与近红外光匹配良好。迄今为止，这类器件通常被悬浮以抑制声子向衬底的辐射损耗，但悬浮会限制热锚定，进而导致过量噪声。无释放型声子晶体已成为应对这一挑战的方案，但此前尚未证明其可与强机电相互作用兼容。本文展示了一种无释放型声子晶体腔，其与高阻抗微波谐振器强耦合，机电耦合率$g_\text{em}/(2π)≈30\thinspace\text{MHz}$，超过机械和微波损耗率，共振时合作度可达$\text{C}≈180$。此外，我们的铌酸锂声子晶体在毫开尔文温度下，于硅和蓝宝石衬底上均达到$10^4$以上的品质因子。我们的研究成果确立了无释放型声子晶体作为紧凑、可扩展的微波与千兆赫兹声波接口，可应用于新兴传感、通信和计算系统。
英文摘要
Phonons hold promise for storing and transferring quantum information, including in mechanically-mediated quantum interconnects between superconducting qubits and light. Phononic crystal cavities confine gigahertz sound to micron-scale volumes well matched to near-infrared light. So far, these devices have typically been suspended to suppress phononic radiation loss into the substrate, but suspension limits thermal anchoring leading to excess noise. Release-free phononic crystals have emerged as a way to address this challenge -- but had yet to be shown compatible with strong electromechanical interactions. Here, we demonstrate a release-free phononic crystal cavity strongly coupled to a high-impedance microwave resonator, with an electromechanical coupling rate $g_\mathrm{em}/(2π) \approx 30\,\text{MHz}$ that exceeds both the mechanical and microwave loss rates, leading to a cooperativity up to $\mathcal{C} \approx 180$ on resonance. In addition, our lithium niobate phononic crystals reach quality factors above $10^4$ at millikelvin temperature on both silicon and sapphire substrates. Our results establish release-free phononic crystals as compact, scalable interfaces between microwaves and gigahertz sound for emerging sensing, communication, and computing systems.
Comments19 pages, 16 figures, 2 tables
