Collisions of ultracold molecules in bright and dark optical dipole traps

Abstract

Understanding collisions between ultracold molecules is crucial for making stable molecular quantum gases and harnessing their rich internal degrees of freedom for quantum engineering. Transient complexes can strongly influence collisional physics, but in the ultracold regime, key aspects of their behavior have remained unknown. To explain experimentally observed loss of ground-state molecules from optical dipole traps, it was recently proposed that molecular complexes can be lost due to photo-excitation. By trapping molecules in a repulsive box potential using laser light near a narrow molecular transition, we are able to test this hypothesis with light intensities three orders of magnitude lower than what is typical in red-detuned dipole traps. This allows us to investigate light-induced collisional loss in a gas of nonreactive fermionic ${}^{23}$Na${}^{40}$K molecules. Even for the lowest intensities available in our experiment, our results are consistent with universal loss, meaning unit loss probability inside the short-range interaction potential. Our findings disagree by at least two orders of magnitude with latest theoretical predictions, showing that crucial aspects of molecular collisions are not yet understood, and provide a benchmark for the development of new theories.

13 pages, 11 figures

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Cited by in corpus (49)

• Quantum Gases in Optical Boxes
• Evaporation of microwave-shielded polar molecules to quantum degeneracy
• Observation of Bose-Einstein Condensation of Dipolar Molecules
• Quantum state manipulation and cooling of ultracold molecules
• Bimolecular chemistry in the ultracold regime
• Transition from a polaronic condensate to a degenerate Fermi gas of heteronuclear molecules
• Probing photoinduced two-body loss of ultracold non-reactive bosonic ${}^{23}$Na${}^{87}$Rb and ${}^{23}$Na${}^{39}$K molecules
• Ultracold Gas of Dipolar NaCs Ground State Molecules
• Ultracold Sticky Collisions: Theoretical and Experimental Status
• Microwave shielding of bosonic NaRb molecules
• A Feshbach resonance in collisions between ultracold ground state molecules
• Reactions Between Layer-Resolved Molecules Mediated by Dipolar Exchange
• Diatomic molecules of alkali-metal and alkaline-earth-metal atoms: interaction potentials, dipole moments, and polarizabilities
• Seconds-scale coherence on nuclear spin transitions of ultracold polar molecules in 3D optical lattices
• High density loading and collisional loss of laser cooled molecules in an optical trap
• On the Stability of the Repulsive Fermi Gas with Contact Interactions
• Molecular Laser-Cooling in a Dynamically Tunable Repulsive Optical Trap
• Resonant and first-order dipolar interactions between ultracold molecules in static and microwave electric fields
• Complexes formed in collisions between ultracold alkali-metal diatomic molecules and atoms
• Collisional losses of ultracold molecules due to intermediate complex formation
• Resonant control of elastic collisions between ${}^{23}$Na${}^{40}$K molecules and ${}^{40}$K atoms
• Hyperfine-to-rotational energy transfer in ultracold atom-molecule collisions
• Robust nuclear spin entanglement via dipolar interactions in polar molecules
• Measurement of the tune-out wavelength for ${}^{133}$Cs at $880$ nm
• Two-photon optical shielding of collisions between ultracold polar molecules
• Four-body singlet potential energy surface for reactions of calcium monofluoride
• Observation of Anomalous Decay of a Polarized Three-Component Fermi Gas
• Hyperfine dependent atom-molecule loss analyzed by the analytic solution of few-body loss equations
• Electric field dependence of complex-dominated ultracold molecular collisions
• Symmetry breaking in sticky collisions between ultracold molecules
• Dynamics of a buffer-gas-loaded, deep optical trap for molecules
• Long-lived fermionic Feshbach molecules with tunable $p$-wave interactions
• Atomic boson-fermion mixtures in 1D box potentials: Few-body and mean-field many-body analyses
• Microscopy of an ultranarrow Feshbach resonance using a laser-based atom collider: A quantum defect theory analysis
• Coherence of Symmetry-Protected Rotational Qubits in Cold Polyatomic Molecules
• Resonances in non-universal dipolar collisions
• Interactions of Ions and Ultracold Neutral Atom Ensembles in Composite Optical Dipole Traps: Developments and Perspectives
• An efficient method to generate near-ideal hollow beams of different shapes for box potential of quantum gases
• Engineering long-range interactions between ultracold atoms with light
• Ultracold Interactions between Ions and Polar Molecules
• Dissipative Superfluidity in a Molecular Bose-Einstein Condensate
• Macroscopic Particle Transport in Dissipative Long-Range Bosonic Systems
• Lossy Quantum Defect Theory of Ultracold Molecular Collisions
• CaF+CaF interactions in the ground and excited electronic states: implications for collisional losses
• Molecule-molecule and atom-molecule collisions with ultracold RbCs molecules
• Ab initio study of the reactivity of ultracold RbSr$+$RbSr collisions
• Strongly dipolar molecular Bose-Einstein condensates: From few- to many-body physics
• Metastable ferromagnetic clusters in dissipative many-body systems of polar molecules
• Model for two-body collisions between ultracold dipolar molecules around a Förster resonance in an electric field