Phase-insensitive amplifier for quantum measurements

精密测量一直是推动现代科学发展的主要动力。特别是光学干涉仪可以直接探测到来自黑洞和中子星的引力波，也可以应用于轴子暗物质探测。但是我们怎样才能进一步改进光学测量呢？它们精度的基本限制来自于光的量子特性。克服量子极限的典型方法是利用光的非经典压缩态。经过几十年的发展，它变得成熟，但也达到了硬极限，从光损耗破坏量子退相干。在这个项目中，我们将探索一种新的范例，使用量子放大来补充压缩技术，并且对光学损耗具有鲁棒性。该创新涉及对相位不敏感放大过程的探索，该过程导致光学干涉仪中的信号和噪声的不对称放大。我们将进行光机械放大器的首次实验研究，并从理论上研究最佳放大方案。我们的发现可能会导致一类新的量子技术，并将对高精度探测器产生广泛的影响。

Precision measurement has been a primary driving force for advancing modern science. In particular, optical interferometers lead to the direct detection of gravitational waves from black holes and neutron stars, and can also be applied for axion dark matter detection. But how can we further improve optical measurements? The fundamental limit to their precision comes from the quantum nature of light. The canonical approach to overcoming the quantum limit is using the non-classical squeezed state of light. After decades of developments, it becomes full-fledged, but also reaches the hard limit from the optical loss that destroys the quantum decoherence. In this project, we will explore a new paradigm using quantum amplification that complements the squeezing technique and is robust against optical loss. The novelty involves an exploration of a phase-insensitive amplification process that leads to an asymmetrical amplification of the signal and the noise in optical interferometers. We will perform the first experimental study of an optomechanical amplifier and theoretically investigate the optimal amplification scheme. Our findings can lead to a new class of quantum techniques and will have a broad impact on high-precision detectors.