Controllable electrostatic surface storage ring with opened optical access for cold polar molecules on a chip

摘要

In order to meet the demands for laser manipulations and detection of cold molecules, we propose an optically accessible and controllable electrostatic surface storage ring for cold polar molecules on a chip, which is one based on extension and application of the three-wire surface guiding scheme [J. Opt. Soc. Am. B 25, 1214 (2008)]. To our knowledge, this is the first real surface storage ring scheme. The spatial distribution of the electrostatic fields generated by two insulator-embedded charged rings and a grounded conductor plate is numerically calculated. Relationships between the height of the trap center above the surface and the setup parameters are analyzed in detail. Using OH radical molecules as a tester, the range of molecular velocities that the storage ring can confine is investigated. The dynamical process of weak-field-seeking OH molecules of state jJ;KMi = j3∕2; ? 9∕4i being loaded into and confined in the storage ring is studied using Monte Carlo simulations. Dependencies of translational temperature of molecules and their trapping efficiency in the storage ring on parameters of the setup and the initial molecular beam are examined. By incorporating a bunching function into our scheme, the number of round trips a trapped molecular packet makes can be improved by almost three times before getting spread out to fill the whole storage ring, as confirmed by numerical simulations.