The next generation of ultralight dark matter (DM) direct detection experiments, which could confirm sub-eV bosons as the dominant source of DM, will feature multiple detectors operating at various terrestrial locations. As a result of the wave-like nature of ultralight DM, spatially separated detectors will each measure a unique DM phase. When the separation between experiments is comparable to the DM coherence length, the spatially-varying phase contains information beyond that which is accessible at a single detector. We introduce a formalism to extract this information, which performs interferometry directly on the DM wave. In particular, we develop a likelihood-based framework that combines data from multiple experiments to constrain directional information about the DM phase space distribution. We show that the signal in multiple detectors is subject to a daily modulation effect unique to wave-like DM. Leveraging daily modulation, we illustrate that within days of an initial discovery multiple detectors acting in unison could localize directional parameters of the DM velocity distribution such as the direction of the solar velocity to sub-degree accuracy, or the direction of a putative cold DM stream to the sub-arcminute level. We outline how to optimize the locations of multiple detectors with either resonant cavity (such as ADMX or HAYSTAC) or quasistatic (such as ABRACADABRA or DM-Radio) readouts to have maximal sensitivity to the full 3-dimensional DM velocity distribution.
Ultralight dark matter detection with trapped-ion interferometry
Walter Burke Institute for Theoretical Physics, California Institute of Technology（加州理工学院沃尔特·伯克理论物理研究所）；Institut de Física d’Altes Energies (IFAE), The Barcelona Institute of Science and Technology（巴塞罗那科学技术高等能源物理研究所）；Institució Catalana de Recerca i Estudis Avançats (ICREA)（加泰罗尼亚高级研究学院）；Department of Physics, King’s College London（伦敦国王学院物理系）；Theoretical Physics Department, CERN（欧洲核子研究中心理论物理部）；Département de Physique Théorique, Université de Genève（日内瓦大学理论物理系）
Enhanced Dark Matter Quantum Sensing via Phase-Space Geometric Interferometry
International Center for Quantum-field Measurement Systems for Studies of the Universe and Particles (QUP, WPI), High Energy Accelerator Research Organization (KEK)（宇宙与粒子研究量子场测量系统国际中心（QUP，WPI），高能加速器研究机构（KEK））；Kavli IPMU (WPI), UTIAS, University of Tokyo（Kavli 宇宙起源研究所（WPI），东京大学宇宙线研究所（UTIAS））
Matter Wave Interferometry for Inertial Sensing and Tests of Fundamental Physics
甚长基线原子干涉测量（VLBAI）是在空间和时间上进行大尺度的地基原子物质波干涉测量，原子波函数经过几秒的自由演化时间或几米尺度的波包分离后进行干涉。作为惯性传感器，例如，这些器件利用了首阶相移随自由演化时间的二次缩放来增强它们的灵敏度，从而产生了引人注目的实验。由于在地平线上1 s处的散粒噪声限制不稳定性优于$10^{-9}$ m/s $^2$，VLBAI可以与最先进的超导重力仪竞争，同时提供绝对测量而不是相对测量。当同时使用多个原子状态、同位素或物质时，可以在$10^{13}$及更高水平上测试自由降落的普遍性。最后，干涉仪的大空间范围允许人们在宏观尺度上探测相干性的极限，以及量子力学和引力的相互作用。我们报告的VLBAI设施的地位，其主要特点，在基础科学和未来的前景。
A Nuclear Interferometer for Ultra-Light Dark Matter Detection
CERN（欧洲核子研究中心）；University of Cambridge（剑桥大学）；Leibniz Universität Hannover（汉诺威莱布尼茨大学）；Physikalisch-Technische Bundesanstalt (PTB)（德国联邦物理技术研究院）；Deutsches Elektronen-Synchrotron DESY（德国电子同步加速器）
