Trampolines Sense a Disturbance in the Force Researchers have engineered trampoline resonators that may be able to sense extremely weak forces and display quantum behavior at ambient temperatures.
Strained membrane resonators have emerged as a promising platform for optomechanical accelerometry; however, the desired combination of low frequency and high Q-mass product requires a rethinking of their dissipation dilution engineering. Applying Bayesian optimization to a Si3N4 membrane, we discover a class of sail-like trampoline resonators in which the frequency is decreased by an order of magnitude while preserving the Q-mass product. We demonstrate centimeter-scale sails with kHz frequencies, Q∼107 and Q×mass∼ 10 g. Vertically integrating a 7 kHz device with a nanoribbon, we realize a monolithic cavity optomechanical accelerometer with a room temperature thermal noise of 40ng0/Hz, sufficient to resolve μg0/Hz ambient vibration over a bandwidth of 4 kHz with a displacement imprecision of 10−14m/Hz. Cryogenic arrays of sail membranes may be attractive for new physics searches and distributed quantum sensing experiments.
Abstract It belongs to a hot topic to sense or detect the weak and even ultra-weak physical quantities by utilizing quantum platforms and methods. We here propose a hybrid magnon-photon system of the yttrium iron garnet (YIG) magnon mode coupled to a microwave cavity, which also includes another degree of freedom with respect to the thermal vibration of this YIG microsphere. In this quasi-tripartite coupling system, we generalize the condition for satisfying energy degeneracy and anti-crossing behaviors. Especially around the zero-energy area, we can get the joint quantum effects of anti-crossing behavior and degeneracy of systemic energy, and then reach a significantly enhanced sensitivity to this phase disturbance. Therefore our proposal can characterize this weak vibration through a phase disturbance and indicate a group of clearly resolvable output spectra. This investigation may be considered as an encouraging attempt on sensing weak quantity by engineering the systemic energy into the critical area for further enlarging its sensitivity to the weak disturbance.