Shielding collisions of ultracold CaF molecules with static electric fields

Abstract

We study collisions of ultracold CaF molecules in strong static electric fields. These fields allow the creation of long-range barriers in the interaction potential, effectively preventing the molecules from reaching the short-range region where inelastic and other loss processes are likely to occur. We carry out coupled-channel calculations of rate coefficients for elastic scattering and loss. We develop an efficient procedure for including energetically well-separated rotor functions in the basis set via a Van Vleck transformation. We show that shielding is particularly efficient for CaF and allows the rate of two-body loss processes to be reduced by a factor of $10^7$ or more at a field of 23 kV/cm. The loss rates remain low over a substantial range of fields. Electron and nuclear spins cause strong additional loss in some small ranges of field, but have little effect elsewhere. These results pave the way for evaporative cooling of CaF towards quantum degeneracy.

18 pages, 21 figures

References in corpus (12)

• A High Phase-Space-Density Gas of Polar Molecules
• Ultracold dense samples of dipolar RbCs molecules in the rovibrational and hyperfine ground state
• Strongly correlated 2D quantum phases with cold polar molecules: controlling the shape of the interaction potential
• Ultracold Dipolar Gas of Fermionic ${}^{23}$Na${}^{40}$K Molecules in their Absolute Ground State
• Creation of ultracold ${}^{87}$RbCs molecules in the rovibrational ground state
• Stabilizing a purely dipolar quantum gas against collapse
• Schemes for robust quantum computation with polar molecules
• Cold polar molecules in 2D traps: Tailoring interactions with external fields for novel quantum phases
• Feshbach resonances in ultracold atomic and molecular collisions: threshold behaviour and suppression of poles in scattering lengths
• Dynamics of ultracold molecules in confined geometry and electric field
• Adimensional theory of shielding in ultracold collisions of dipolar rotors
• Tuning ultracold collisions of excited rotational dipolar molecules

Cited by in corpus (9)

• Observation of generalized t-J spin dynamics with tunable dipolar interactions
• Ultracold LiCr: a new pathway to quantum gases of paramagnetic polar molecules
• SU(N) magnetism with ultracold molecules
• Controlling collisional loss and scattering lengths of ultracold dipolar molecules with static electric fields
• Collisions of Spin-polarized YO Molecules for Single Partial Waves
• SU($N$) symmetry with ultracold alkali dimers: weak dependence of scattering properties on hyperfine state
• A quantum Monte Carlo based density functional for Dysprosium dipolar system
• Hyperfine van der Waals repulsion between open-shell polar molecules
• Strongly dipolar molecular Bose-Einstein condensates: From few- to many-body physics