Nuclear T-violation searches using ultracold atoms and molecules

使用超冷原子和分子进行核 T 违规搜索

• 批准号: SAPIN-2021-00025
• 负责人: Vutha, Amar
• 金额: $ 6.78万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Subatomic Physics Envelope - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=762720
• 关键词: Nuclear; violation; searches; using; ultracold

The origin of the matter-antimatter asymmetry of the universe is one of the deepest open questions in fundamental physics. This asymmetry is believed to arise from microscopic time-reversal symmetry violation (T-violation) occuring at extremely high energy scales. Although such energies are beyond the present reach of colliders, atomic nuclei can act as "antennas" for this new physics, revealing clues through precision measurements of their nuclear symmetries. Measurements of nuclear T-violation can achieve extremely high sensitivity to new physics by using laser-cooled and trapped atoms and molecules held at ultracold temperatures (in the micro-kelvin regime). The measurements also benefit by using octupole-deformed nuclei such as 225Ra, which have a large intrinsic sensitivity to nuclear T-violation. Incorporating the nuclei within a polar molecule enhances the measurable physics effects even further, due to the large electric fields applied to the nuclei by the electrons. The research program described here aims to develop a world-leading nuclear T-violation experiment by taking advantage of all of these factors. It will leverage many of the latest techniques from atomic and molecular physics. This program will (a) use laser-cooled atoms trapped in a reconfigurable array of optical tweezers: trapped atoms lead to higher precision measurements, and atoms in tweezer arrays can be placed in entangled states to boost the precision of measurements using quantum correlations. The program will also (b) investigate the use of polar molecules containing octupole-deformed nuclei, which can be  assembled from laser-cooled atoms at extremely low temperatures: ultracold molecular assembly offers an established path towards production of trapped molecules,. The combination of these three ingredients -- octupole-deformed nucleus, polar molecule and quantum entanglement in an optical trap array -- will open a path to experiments with more than thousand-fold higher sensitivity to T-violation compared to the state of the art. This research program will take advantage of the latest developments in the fields of atomic physics and quantum information science, and apply them to a specific fundamental physics task: measuring nuclear T-violation with unprecedented sensitivity. This program will be the first of its kind in the world. It will enable my group to attract excellent students and postdocs, and generate a cohort of skilled personnel with unique training in the latest techniques of precision subatomic physics. The research program aims to discover fundamental scientific truths, but its position at the high-technology frontier also makes it certain that it will lead to technological spin-offs. The program of research will also have a substantial scientific back-action on atomic physics and quantum information science, generating new ideas to advance subatomic physics.

宇宙物质与反物质不对称性的起源是基础物理学中最深刻的开放性问题之一。这种不对称性被认为是由在极高能量尺度上发生的微观时间反转对称性破坏（T-破坏）引起的。尽管这样的能量超出了目前对撞机的范围，但原子核可以充当这种新物理学的“天线”，通过精确测量其核对称性来揭示线索。通过使用激光冷却和捕获在超冷温度（微开尔文状态）下的原子和分子，核 T 破坏的测量可以实现对新物理的极高灵敏度。这些测量还受益于使用八极变形核，例如 225Ra，它对核 T 破坏具有很大的内在敏感性。由于电子向原子核施加了大电场，因此将原子核纳入极性分子中可以进一步增强可测量的物理效应。 这里描述的研究计划旨在利用所有这些因素开发世界领先的核 T 违规实验。它将利用原子和分子物理学的许多最新技术。该计划将（a）使用捕获在可重构光镊阵列中的激光冷却原子：捕获的原子可以实现更高精度的测量，并且镊子阵列中的原子可以处于纠缠态，以提高使用量子相关性的测量精度。该计划还将 (b) 研究含有八极变形核的极性分子的使用，这些分子可以在极低的温度下由激光冷却的原子组装而成：超冷分子组装提供了一条生产捕获分子的既定途径。这三种成分——八极变形核、极性分子和光陷阱阵列中的量子纠缠——的结合将为实验开辟一条道路，与现有技术相比，对 T 破坏的灵敏度要高出千倍以上。 该研究计划将利用原子物理学和量子信息科学领域的最新发展，并将其应用于特定的基础物理任务：以前所未有的灵敏度测量核T破坏。该计划将是世界上同类计划中的第一个。它将使我的团队能够吸引优秀的学生和博士后，并培养一批在精密亚原子物理最新技术方面接受过独特培训的技术人员。该研究项目旨在发现基本的科学真理，但其在高科技前沿的地位也使其肯定会带来技术副产品。该研究计划还将对原子物理学和量子信息科学产生重大的科学反作用，产生推进亚原子物理学的新想法。