论文标题
噪音感测和暗物质搜索的最终精确限制
Ultimate precision limit of noise sensing and dark matter search
论文作者
论文摘要
暗物质的性质是未知的，需要进行系统的搜索。对于Axion暗物质，此类搜索依赖于发现由于暗物质和微波卤素之间的弱耦合而引起的微弱随机噪声。我们将这些过程建模为量子通道，并得出噪声传感的基本精度极限。因此，基于两种模式挤压真空的纠缠辅助策略表现出最佳状态，而单模挤压真空的最佳性仅限于无损情况。我们提出了“无效”测量（挤压和光子计数），以实现最佳性能。就扫描速率而言，即使有20个强度的贝贝尔，单模挤压仍然不足以实现真空极限，这是通过对真空输入的光子计数来实现的。虽然两种模式挤压的真空吸尘器在真空极限上提供了较大且接近最接近的优势，因此不再需要更多的异国量子资源。我们的结果强调了在暗物质搜索中进行纠缠辅助和微波光子计数的必要性。
The nature of dark matter is unknown and calls for a systematical search. For axion dark matter, such a search relies on finding feeble random noise arising from the weak coupling between dark matter and microwave haloscopes. We model such process as a quantum channel and derive the fundamental precision limit of noise sensing. An entanglement-assisted strategy based on two-mode squeezed vacuum is thereby demonstrated optimal, while the optimality of a single-mode squeezed vacuum is found limited to the lossless case. We propose a `nulling' measurement (squeezing and photon counting) to achieve the optimal performances. In terms of the scan rate, even with 20-decibel of strength, single-mode squeezing still underperforms the vacuum limit which is achieved by photon counting on vacuum input; while the two-mode squeezed vacuum provides large and close-to-optimum advantage over the vacuum limit, thus more exotic quantum resources are no longer required. Our results highlight the necessity of entanglement assistance and microwave photon counting in dark matter search.
