We propose using optomechanical interaction to narrow the bandwidth of filter cavities for achieving frequency-dependent squeezing in advanced gravitational-wave detectors, inspired by the idea of optomechanically induced transparency. This not only allows us to achieve narrow bandwidth, comparable to the detection band of few hundred Hz, with tabletop optical cavities, but also to tune the bandwidth over a wide range, which is ideal for optimizing sensitivity for different gravitational-wave sources. The experimental challenge for its implementation is the stringent requirement on low thermal noise, which would need superb mechanical quality factor that is quite difficult to achieve by using currently-available low-loss mechanical oscillators; one possible solution is to use optical dilution of the mechanical damping, which can considerably relax the requirement on the mechanics.
We propose a scheme that can generate a tunable double optomechanically induced transparency (OMIT) in a hybrid optomechanical cavity system, in which the mechanical resonator of an optomechanical cavity is coupled to an additional mechanical resonator, and the additional mechanical resonator can be driven by a weak external coherently mechanical driving field. We show that both the intensity and the phase of the the external mechanical driving field can control the propagation of the probe field, including changing the transmission spectrum curve from a double-window to a single-window. Our s…
We study theoretically an optical cavity and a parity-time ($\mathcal{PT}$)-symmetric pair of mechanical resonators, where all oscillators are pairwise coupled, forming an optomechanical system with a closed-contour interaction. Due to the presence of both gain and feedback, we explore its stability and the root loci over a wide coupling range. Under the red-sideband pumping and for the so-called $\mathcal{PT}$-unbroken phase it displays a double optomechanically induced transparency (OMIT) for an experimentally realizable parameter set. We show that both the transmission amplitude and the gro…
We study tunable optomechanically induced transparency by controlling the dark-mode effect induced by two mechanical modes coupled to a common cavity field. This is realized by introducing a phase-dependent phonon-exchange interaction, which is used to form a loop-coupled configuration. Combining this phase-dependent coupling with the optomechanical interactions, the dark-mode effect can be controlled by the quantum interference effect. In particular, the dark-mode effect in this two-mechanical-mode optomechanical system can lead to a double-amplified optomechanically induced transparency (OMI…
We discuss the design of quantum hybrid inertial sensor that combines an optomechanical inertial sensor with the retro-reflector of a cold atom interferometer. This sensor fusion approach provides absolute and high accuracy measurements with cold atom interferometers, while utilizing the optomechanical inertial sensor at frequencies above the repetition rate of the atom interferometer. This improves the overall measurement bandwidth as well as the robustness and field deployment capabilities of these systems. We evaluate which parameters yield an optimal acceleration sensitivity, from which we…
Quantum noise limits the sensitivity of precision measurement devices, such as laser interferometer gravitational-wave observatories and axion detectors. In the shot-noise-limited regime, these resonant detectors are subject to a trade-off between the peak sensitivity and bandwidth. One approach to circumvent this limitation in gravitational-wave detectors is to embed an anomalous-dispersion optomechanical filter to broaden the bandwidth. The original filter cavity design, however, makes the entire system unstable. Recently, we proposed the coherent feedback between the arm cavity and the opto…
We consider an optomechanical cavity with a movable end-mirror as a quantum mechanical oscillator (MO) containing an interacting cigar-shaped Bose-Eisenstein condensate (BEC). It is assumed that both the MO and the BEC interact with the radiation pressure of the cavity field in the red-detuned and weak coupling regimes while the two-body atomic collisions frequency of the BEC and the mechanical spring coefficient of the MO are coherently modulated. By analyzing the scattering matrix we find that a frequency-dependent squeezing is induced to the three subsystems only due to the coherent modulat…
We consider using optomechanical accelerometers as resonant detectors for ultralight dark matter. As a concrete example, we describe a detector based on a silicon nitride membrane fixed to a beryllium mirror, forming an optical cavity. The use of different materials gives access to forces proportional to baryon (B) and lepton (L) charge, which are believed to be coupling channels for vector dark matter particles ("dark photons"). The cavity meanwhile provides access to quantum-limited displacement measurements. For a centimeter-scale membrane pre-cooled to 10 mK, we argue that sensitivity to v…
We investigate a theoretical demonstration of perfect frequency conversion in an optomechanical system in the weak coupling regime without a Stokes side-band. An optomechanical cavity illuminated by a weak probe field generates two side-modes, differentiating from the original signal by a phonon frequency. We report the presence of a special combination of parameters in the weak-coupling regime, where Stokes side-mode vanishes exactly. Only the anti-Stokes mode is observed with a few hundreds Hz spectral bandwidth of the probe field. Emergence of this special point is totally unrelated with th…
We provide a fully analytical treatment for the partial refrigeration of the thermal motion of a quantum mechanical resonator under the action of feedback. As opposed to standard cavity optomechanics where the aim is to isolate and cool a single mechanical mode, the aim here is to extract the thermal energy from many vibrational modes within a large frequency bandwidth. We consider a standard cold-damping technique where homodyne read-out of the cavity output field is fed into a feedback loop that provides a cooling action directly applied on the mechanical resonator. Analytical and numerical …
We investigate how to generate continuous-variable entanglement between distant optomechanical and spin systems, by transferring input two-mode squeezed vacuum state to the system. Such a setup has been proposed for backaction evading gravitational-wave measurement, squeezing the output noise below the standard quantum limit. We find that the spin cavity entanglement saturates to a particular value when no mechanics are involved even though the entanglement of the input beam increases steadily, and drops down when the mechanical oscillator interacts with the cavity. Our study also reveals that…
Cavity Optomechanical Quantum Memory for Twisted Photons Using a Ring BEC
School of Physics and Astronomy, Rochester Institute of Technology（罗切斯特理工学院物理与天文学院）；Department of Physics, Indian Institute of Technology Bombay（印度理工学院孟买分校物理系）；School of Basic Sciences, Indian Institute of Technology Bhubaneswar（印度理工学院布巴内斯瓦尔基础科学学院）；Max Planck Institute for the Science of Light（马克斯·普朗克光科学研究所）；Centre of Excellence in Quantum Information, Computation, Science and Technology, Indian Institute of Technology Bombay（印度理工学院孟买分校量子信息、计算科学与技术卓越中心）
In this paper, the scheme of a force sensor is proposed which has been composed of a hybrid optomechanical cavity containing an interacting cigar-shaped Bose-Einstein condensate (BEC) where the \textit{s}-wave scattering frequency of the BEC atoms as well as the spring coefficient of the cavity moving end-mirror (the mechanical oscillator) are parametrically modulated. It is shown that in the red-detuned regime and under the so-called impedance-matching condition, the mechanical response of the system to the input signal is enhanced substantially, which leads to the amplification of the weak i…
Quantum noise limits in white-light-cavity-enhanced gravitational wave detectors
在此之前，我们已经提出了一个引力波探测器，它采用了白光腔（WLC）效应，使用复合腔信号回收（CC-SR）。在这里，我们首先使用一个理想化的模型为负色散介质（NDM），并使用所谓的洞穴模型的相位不敏感的线性放大器，以占的量子噪声（QN）的NDM贡献，以确定在灵敏度带宽产品的增强的上限。我们计算了CC-SR设计的量子噪声限制的灵敏度曲线，发现经典分析预测的灵敏度的加宽也存在于这些曲线中，但有所减少。此外，我们发现，曲线总是停留在标准量子极限以上。为了克服这一限制，我们修改了色散，以补偿由光机共振效应产生的非线性相位变化。我们发现，与Bunanno和Chen [Phys. Rev. D 64，042006（2001）]预测的最高灵敏度结果相比，灵敏度带宽积增加的因子的上限为~14。我们还提出了一个更简单的方案（WLC-SR），其中色散介质插入到SR腔。对于该方案，我们发现增强因子的上限为~18。然后，我们考虑了一个明确的系统实现NDM，它利用五个能级的M-配置产生增益，伴随着电磁感应透明（GEIT系统）。对于这个显式系统，我们采用严格的方法基于主方程计算的QN贡献的NDM，从而使我们能够确定的灵敏度带宽产品的增强，而不是其上限。具体来说，我们确定了一组参数的灵敏度带宽产品是由17.66的一个因素增强。
