Controlled Collisions between Ultracold Polar Molecules

POSTER

Abstract

A degenerate gas of polar molecules, which interacts via long-range, anisotropic potentials, allows access to rich many-body physics. One challenge of realizing many-body interacting systems is the short molecular lifetime relative to the interaction timescale, which is limited by two-body loss.

By confining the molecules to two dimensions and applying an electric field to polarize the dipoles perpendicular to the plane of motion, we show strong suppression of inelastic loss and a corresponding enhancement of elastic collisions. We use direct molecular evaporation to reach temperatures below the Fermi temperature, and observe a non-classical momentum distribution.

Second, we use a resonant shielding mechanism between pairs of molecular states to reduce inelastic loss in three dimensions while preserving elastic dipole-dipole collisions. The thermalization rate depends on the relative angle of colliding molecules with respect to their dipoles, which is characteristic of anisotropic dipolar interactions. We demonstrate direct evaporation, realizing a long-lived, interacting, bulk molecular gas.

Publication: Valtolina et al., Nature 588, 239-243 (2020)
Matsuda et al., Science 370, 1324-1327 (2020)
Li et al., Submitted (2021)

Presenters

  • William G Tobias

    • JILA and University of Colorado Boulder
    • JILA, University of Colorado Boulder
    • University of Colorado, Boulder

Authors

  • William G Tobias

    • JILA and University of Colorado Boulder
    • JILA, University of Colorado Boulder
    • University of Colorado, Boulder

  • Jun-Ru Li

    • JILA and University of Colorado Boulder
    • JILA, University of Colorado Boulder
    • JILA

  • Kyle Y Matsuda

    • JILA and University of Colorado Boulder
    • JILA, University of Colorado Boulder
    • University of Colorado, Boulder

  • Calder Miller

    • JILA and University of Colorado Boulder
    • JILA, University of Colorado Boulder

  • Giacomo Valtolina

    • JILA and University of Colorado Boulder
    • JILA, University of Colorado Boulder
    • University of Colorado, Boulder

  • Jun Ye

    • JILA and University of Colorado Boulder
    • JILA, University of Colorado, Boulder
    • University of Colorado, Boulder
    • JILA, NIST, and University of Colorado Boulder
    • JILA, University of Colorado Boulder
    • JILA, University of Colorado and National Institute of Standards and Technology, and Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
    • JILA, National Institute of Standards and Technology and Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
    • JILA, NIST, and Department of Physics, University of Colorado, Boulder
    • JILA, NIST, and University of Colorado, Boulder
    • JILA, NIST, and University of Colorado at Boulder