2008/11/30 by M. R. Tarbutt, J. J. Hudson, B. E. Sauer +1
Physics and Astronomy · #Chemical polarity #Coherence (philosophical gambling strategy) #Cold Atom Physics and Bose-Einstein Condensates #Dipole #Electric dipole moment #Electric field #Electron #Laser-Matter Interactions and Applications #Mechanical and Optical Resonators #Molecular beam #Moment (physics) #Perpendicular #Stark effect #physics.atom-ph
paper · pdf · doi:10.1039/b820625b
published as Faraday Discussions 142, 37 (2009) · 22 pages, 7 figures, prepared for Faraday Discussion 142
openalex publication_date 2009/01/01 · arxiv created 2010/01/29 · arxiv updated 2010/02/08 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Heavy polar molecules can be used to measure the electric dipole moment of the electron, which is a sensitive probe of physics beyond the Standard Model. The value is determined by measuring the precession of the molecule's spin in a plane perpendicular to an applied electric field. The longer this precession evolves coherently, the higher the precision of the measurement. For molecules in a trap, this coherence time could be very long indeed. We evaluate the sensitivity of an experiment where neutral molecules are trapped electrically, and compare this to an equivalent measurement in a molecular beam. We consider the use of a Stark decelerator to load the trap from a supersonic source, and calculate the deceleration efficiency for YbF molecules in both strong-field seeking and weak-field seeking states. With a 1 s holding time in the trap, the statistical sensitivity could be ten times higher than it is in the beam experiment, and this could improve by a further factor of five if the trap can be loaded from a source of larger emittance. We study some effects due to field inhomogeneity in the trap and find that rotation of the electric field direction, leading to an inhomogeneous geometric phase shift, is the primary obstacle to a sensitive trap-based measurement.