Nuclear T-violation searches using ultracold atoms and molecules

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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.