标题： 干涉仪读出噪声低于膜的标准量子极限 显示英文标题

标题： Interferometer readout-noise below the Standard Quantum Limit of a membrane

摘要： 此处我们报告了一种Michelson-Sagnac干涉仪的实现，其目的是对表现出显著光透射的膜的运动进行精确表征。 我们的干涉仪在约100 kHz的SiN_x膜的基本共振频率附近的读出噪声谱密度（不精确度）为3E-16 m/sqrt(Hz)，而无需使用光学腔。 所展示的读出噪声比膜的标准量子极限（SQL）峰值低超过16 dB。 这种降低幅度明显高于以前使用纳米线的工作[Teufel等，Nature Nano. 4, 820 (2009); Anetsberger等，Nature Phys. 5, 909 (2009)]。 我们讨论了SQL对于力测量的意义及其与读出性能的关系，并得出结论，无论是我们的实验还是以前的实验，都没有达到如此低的总噪声谱密度。 显示英文摘要

摘要： Here we report on the realization of a Michelson-Sagnac interferometer whose purpose is the precise characterization of the motion of membranes showing significant light transmission. Our interferometer has a readout noise spectral density (imprecision) of 3E-16 m/sqrt(Hz) at frequencies around the fundamental resonance of a SiN_x membrane at about 100 kHz, without using optical cavities. The readout noise demonstrated is more than 16 dB below the peak value of the membrane's standard quantum limit (SQL). This reduction is significantly higher than those of previous works with nano-wires [Teufel et al., Nature Nano. 4, 820 (2009); Anetsberger et al., Nature Phys. 5, 909 (2009)]. We discuss the meaning of the SQL for force measurements and its relation to the readout performance and conclude that neither our nor previous experiments achieved a total noise spectral density as low as the SQL.