ABSTRACT
We demonstrate a method to enhance the atom loading rate of a ytterbium (Yb) magneto-optic trap (MOT) operating on the 556 nm 1S0 â 3P1 intercombination transition (narrow linewidth Γg = 2π × 182 kHz). Following traditional Zeeman slowing of an atomic beam near the 399 nm 1S0 â 1P1 transition (broad linewidth Γp = 2π × 29 MHz), two laser beams in a crossed-beam geometry, frequency tuned near the same transition, provide additional slowing immediately prior to the MOT. Using this technique, we observe an improvement by a factor of 6 in the atom loading rate of a narrow-line Yb MOT. The relative simplicity and generality of this approach make it readily adoptable to other experiments involving narrow-line MOTs. We also present a numerical simulation of this two-stage slowing process, which shows good agreement with the observed dependence on experimental parameters, and use it to assess potential improvements to the method.
ABSTRACT
We demonstrate the scale up of a symmetric three-path contrast interferometer to large momentum separation. The observed phase stability at separation of 112 photon recoil momenta exceeds the performance of earlier free-space interferometers. In addition to the symmetric interferometer geometry and Bose-Einstein condensate source, the robust scalability of our approach relies on the suppression of undesired diffraction phases through a careful choice of atom optics parameters. The interferometer phase evolution is quadratic with number of recoils, reaching a rate as high as 7×10^{7} rad/s. We discuss the applicability of our method towards a new measurement of the fine-structure constant and a test of QED.