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New tools for quantum sensing with polarized spins

Kolloquium der Abteilung 8

Two different approaches for performing precision measurements with spin-polarized quantum systems will be presented. Both are motivated by the quest to measure finite permanent electric dipole moments (EDMs), a signature of new CP-violating physics that is needed to explain the presence of matter in our universe.


Warm noble-gas vapors offer a robust platform for precision measurements, but present many practical challenges for creating and detecting nuclear spin polarization. Thus, new approaches for direct optical probes of ground-state noble-gas spin-polarization, including the status of ongoing proof-of-principle measurements will be discussed. Multi-photon transitions enable new detection methods complementary to the use of SQUIDs or other magnetometers, as well as possibilities to constrain certain systematic errors via new degrees of freedom arising from nonlinear optics.


Ultracold neutrons offer a complementary platform for precision studies of CP-violation in the strong sector, without semileptonic interactions. While they are perhaps more challenging to create and detect than hyperpolarized noble gases, comparable physics reach can be obtained with orders-of-magnitude fewer particles. Therefore, modern superthermal production of ultracold neutrons, and the prospects for new progress in a field that for decades has been strongly limited by statistics will be another subject of the talk.