Optically measuring force near the standard quantum limit

0.1, consistent with a small finite microwave occupation factor (n c ≈ 0.6 T 0.1) in addition to the quantum fluctuations. In contrast, we do not observe a large increase in the mechanical fluctuations in BAE as the imprecision decreases (red dots in Quantum fluctuations of a single mode in a microwave field can be sensed with a mechanical system, and, with the proper pump field, these fluctuations can be steered into an unobserved aspect of the motion. These results lead the way toward measuring and manipulating the quantum noise of a mechanical resonator. As described i