AI 中文总结
该研究针对结构阻尼产生的1/f力噪声谱损害宏观纠缠的问题，研制出7毫克的阶梯式熔融石英纤维悬挂摆，测得增益超出所需要求，为宏观纠缠实现提供了可行方案。
AI 中文摘要
摆因重力稀释可降低机械损耗，故在宏观量子控制中颇具吸引力，而与结构阻尼相关的1/f力噪声谱可实现近乎无损耗的捕获，以抑制在向上偏移的共振处采样的热噪声。不过，同样的1/f谱会产生低频尾，损害纠缠。在10%的探测损耗下，我们发现该低频尾使所需反作用与热力噪声之比提高了约50%，对应所需悬挂增益G_req=1.49。为克服该结构噪声损害，我们实现了一个7毫克的摆，由阶梯式熔融石英纤维悬挂，在ω0/2π=2.63Hz时，能量衰减率Γ/2π=361(39)nHz（Q≡ω0/Γ=7.3(8)×10^6）。ω0Γ的降低使测得的增益G_q≈2.5，相较于先前的单片器件，超出了要求。
英文摘要
Pendulums are attractive for macroscopic quantum control because gravity dilution reduces mechanical loss, while the $1/f$ force-noise spectrum associated with structural damping allows nearly lossless trapping to suppress the thermal noise sampled at an upward-shifted resonance. The same $1/f$ spectrum, however, produces a low-frequency tail that penalizes entanglement. With $10\%$ detection loss, we find that this tail raises the required back-action-to-thermal force-noise ratio by about $50\%$, corresponding to a required suspension gain $G_{\rm req}=1.49$. To overcome this structural-noise penalty, we realize a $7$-mg pendulum suspended by a stepped fused-silica fiber, with an energy-decay rate $Γ/2π=361(39)$ nHz ($Q\equivω_0/Γ=7.3(8)\times10^6$) at $ω_0/2π=2.63$ Hz. The reduction in $ω_0Γ$ yields a measured gain $G_q\simeq2.5$ relative to the previous monolithic device, exceeding the requirement.
