Colloquium
Physics Lecture Hall
Wednesday, October 22, 2014, 4:45 pm
Tea and cookies @ 4:30 pm
Michael Romalis
(Princeton):
Precision measurements with spin-polarized gases
Spin-polarized gases provide a powerful tool for precision measurements because they typically contain a large number of atoms with a long spin coherence time. They are used for sensitive measurements of magnetic fields as well as other types of interactions that couple to particle spin. I will describe recent advances in the precision of these measurements that allow us to detect very small magnetic fields and enable new applications, for example recording of magnetic fields generated by the brain. Spin-polarized ensembles are also sensitive to several types of interactions beyond the Standard Model, for example, long-range spin-dependent forces and spatial anisotropy due to violation of local Lorentz invariance. To search for such effects, we have installed a sensitive spin sensor at the South Pole, which is a preferred location for such experiments due to alignment of the Earth's rotation direction and the gravity direction.