112 research outputs found
Gravitational Wave Detection with High Frequency Phonon Trapping Acoustic Cavities
There are a number of theoretical predictions for astrophysical and
cosmological objects, which emit high frequency (~Hz) Gravitation
Waves (GW) or contribute somehow to the stochastic high frequency GW
background. Here we propose a new sensitive detector in this frequency band,
which is based on existing cryogenic ultra-high quality factor quartz Bulk
Acoustic Wave cavity technology, coupled to near-quantum-limited SQUID
amplifiers at ~mK. We show that spectral strain sensitivities reaching
per per mode is possible, which in principle can
cover the frequency range with multiple () modes with quality factors
varying between allowing wide bandwidth detection. Due to its
compactness and well established manufacturing process, the system is easily
scalable into arrays and distributed networks that can also impact the overall
sensitivity and introduce coincidence analysis to ensure no false detections.Comment: appears in Phys. Rev. D, (2014
Observation of Low Temperature Magneto-Mechanic Effects in Crystalline Resonant Phonon Cavities
We observe magnetic effects in ultra-high quality factor crystalline quartz
Bulk Acoustic Wave resonators at milli-Kelvin temperature. The study reveals
existence of hysteresis loops, jumps and memory effects of acoustical resonance
frequencies. These loops arise as a response to the external magnetic field and
span over few Hertz range for modes with linewidths of about mHz, which
constitute a frequency shift of order 60 linewidths. The effects are broadband
but get stronger towards higher frequencies where both nonlinear effects and
losses are limited by two level systems. This suggests that the observed
effects are due to ferromagnet-like phase of a spin ensemble coupled to
mechanical modes. The observed coupling between mechanical and spin degrees of
freedom in the ultra low loss regime brings new possibilities for the emerging
class of quantum hybrid systems
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