Polarization-gradient cooling of 1D and 2D ion Coulomb crystals
Manoj K. Joshi, A. Fabre, Christine Maier, Tiff Brydges, Dominik Kiesenhofer, Helene Hainzer, R. Blatt, C. F. Roos
Abstract
Abstract We present experiments on polarization gradient cooling of Ca + multi-ion Coulomb crystals in a linear Paul trap. Polarization gradient cooling of the collective modes of motion whose eigenvectors have overlap with the symmetry axis of the trap is achieved by two counter-propagating laser beams with mutually orthogonal linear polarizations that are blue-detuned from the S 1/2 ↔ P 1/2 transition. We demonstrate cooling of linear chains of up to 51 ions and 2D-crystals in zig-zag configuration with 22 ions. The cooling results are compared with numerical simulations and the predictions of a simple model of cooling in a moving polarization gradient.