Ultracold YbF molecules to measure the electron's electric dipole moment.

ended

The project aims to show that the electron's electric dipole moment (eEDM) could be measured with an unprecedented precision of 10^{-31} e cm by using ultracold polar molecules. Such a measurement would be a demanding test of theories beyond the Standard Model of particle physics, and a search for the undiscovered forces responsible for the observed asymmetry between matter and anti-matter in the Universe. The key advance that will unlock this extraordinary sensitivity is interferometry with molecules cooled to ultracold temperature. I will make an intense, slow-moving beam of YbF molecules, which are known to be exceptionally sensitive to the eEDM. I will then apply laser cooling in both transverse directions to bring the temperature below 50 microkelvin, yielding a highly-collimated molecular beam. Next, I will build a spin interferometer using these ultracold molecules. Finally, by paying careful attention to noise sources, especially magnetic field noise, I will show that the interferometer can reach the sensitivity set by the quantum projection noise. Laser cooling of molecules is a new technique, and I will be the first to use it to enhance the sensitivity of a measurement that tests fundamental physics.