腔内控制的量子增强暗物质探测：缓解瑞利诅咒
Quantum-enhanced dark matter detection with in-cavity control: mitigating the Rayleigh curse
AI总结：
针对微波腔暗物质探测中恒定损耗导致的瑞利诅咒，本文提出腔内量子态制备、可调轴子积累与测量的原位协议，并基于SMSS和TMSS分析量子优势条件及最优测量方案。
摘要：
暗物质的本质是现代物理学中的一个基本谜题。搜索暗物质的一种主要方法依赖于探测微波腔中的微弱噪声。然而，压缩等常见量子资源的量子优势受到瑞利诅咒的内在限制——恒定损耗为这些量子资源设定了灵敏度上限。本文提出一种原位协议以缓解这种瑞利极限。该协议包含三个步骤：腔内量子态制备、持续时间可调的轴子积累以及测量。对于量子源，我们聚焦于单模压缩态（SMSS），以及使用处于双模压缩态（TMSS）的信号-辅助量子比特对的纠缠辅助情形，其中辅助量子比特不与轴子相互作用。通过量子Fisher信息率评估，我们推导了实现量子优势对腔品质因数、热噪声水平和压缩增益的要求。当压缩增益增大时，最佳轴子积累时间会缩短，以减少损耗并缓解瑞利诅咒——量子优势随压缩增益持续提升。总体而言，我们发现TMSS在低温极限下更灵敏。在SMSS情形中，由于相对于真空获得优势需要大增益，零差检测足以实现最优性。对于TMSS，反压缩和光子计数对于达到最优是必要的。得益于抗磁场腔内压缩以及用于光子计数的快速耦合输出的最新进展，所提出的协议与轴子探测场景兼容。
英文摘要：
The nature of dark matter is a fundamental puzzle in modern physics. A major approach of searching for dark matter relies on detecting feeble noise in microwave cavities. However, the quantum advantages of common quantum resources such as squeezing are intrinsically limited by the Rayleigh curse -- a constant loss places a sensitivity upper bound on these quantum resources. In this paper, we propose an in-situ protocol to mitigate such Rayleigh limit. The protocol consists of three steps: in-cavity quantum state preparation, axion accumulation with tunable time duration, and measurement. For the quantum source, we focus on the single-mode squeezed state (SMSS), and the entanglement-assisted case using signal-ancilla pairs in two-mode squeezed state (TMSS), where the ancilla does not interact with the axion. From quantum Fisher information rate evaluation, we derive the requirement of cavity quality factor, thermal noise level and squeezing gain for quantum advantage. When the squeezing gain becomes larger, the optimal axion accumulation time decreases to reduce loss and mitigate the Rayleigh curse -- the quantum advantage keeps increasing with the squeezing gain. Overall, we find that TMSS is more sensitive in the low temperature limit. In the case of SMSS, as large gain is required for advantage over vacuum, homodyne is sufficient to achieve optimality. For TMSS, anti-squeezing and photon counting is necessary to be optimal. Thanks to the recent advance in magnetic-field-resilient in-cavity squeezing and rapidly coupling out for photon counting, the proposed protocol is compatible with axion detection scenario.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
