Getting phonons to hang around The ideal platform for quantum-computing and quantum-sensing applications is likely to be a hybrid system that combines the best features of different components. Superconducting circuits are relatively advanced, and finding components that can control and manipulate the microwaves will be essential. MacCabe et al. explored the use of high-quality microresonators in which the acoustic environment could be engineered such that the phonon lifetime could be extended to more than 1 second. Operating at microwave frequencies of 5 gigahertz, these quantum acoustic-dynamic devices could be coupled with superconducting circuits. Science, this issue p. 840 Engineering of the acoustic environment surrounding a mechanical microresonator is used to extend phonon lifetimes. The energy damping time in a mechanical resonator is critical to many precision metrology applications, such as timekeeping and force measurements. We present measurements of the phonon lifetime of a microwave-frequency, nanoscale silicon acoustic cavity incorporating a phononic bandgap acoustic shield. Using pulsed laser light to excite a colocalized optical mode of the cavity, we measured the internal acoustic modes with single-phonon sensitivity down to millikelvin temperatures, yielding a phonon lifetime of up to τph,0≈1.5 seconds (quality factor Q=5×1010) and a coherence time of τcoh,0≈130 microseconds for bandgap-shielded cavities. These acoustically engineered nanoscale structures provide a window into the material origins of quantum noise and have potential applications ranging from tests of various collapse models of quantum mechanics to miniature quantum memory elements in hybrid superconducting quantum circuits.

中文翻译：

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具有超长声子寿命的纳米声谐振器

让声子四处游荡 量子计算和量子传感应用的理想平台很可能是一个混合系统，它结合了不同组件的最佳特性。超导电路相对先进，找到可以控制和操纵微波的组件将是必不可少的。麦凯布等人。探索了使用高质量微谐振器，其中可以设计声环境，使声子寿命可以延长到 1 秒以上。这些量子声动力学设备以 5 GHz 的微波频率运行，可以与超导电路耦合。科学，这个问题 p。840 机械微谐振器周围的声学环境工程用于延长声子寿命。机械谐振器中的能量阻尼时间对于许多精密计量应用至关重要，例如计时和力测量。我们提出了对包含声子带隙声屏蔽的微波频率、纳米级硅声腔的声子寿命的测量。使用脉冲激光激发腔的共定位光学模式，我们测量了具有低至毫开尔文温度的单声子灵敏度的内部声学模式，产生高达 τph,0≈1.5 秒的声子寿命（品质因数 Q=5× 1010) 和带隙屏蔽腔的相干时间 τcoh,0≈130 微秒。