A Feshbach resonance in collisions between ultracold ground state molecules

Abstract

Collisional resonances are an important tool which has been used to modify interactions in ultracold gases, for realizing novel Hamiltonians in quantum simulations, for creating molecules from atomic gases and for controlling chemical reactions. So far, such resonances have been observed for atom-atom collisions, atom-molecule collisions and collisions between Feshbach molecules which are very weakly bound. Whether such resonances exist for ultracold ground state molecules has been debated due to the possibly high density of states and/or rapid decay of the resonant complex. Here we report a very pronounced and narrow (25 mG) Feshbach resonance in collisions between two ground state NaLi molecules. This molecular Feshbach resonance has two special characteristics. First, the collisional loss rate is enhanced by more than two orders of magnitude above the background loss rate which is saturated at the $p$-wave universal value, due to strong chemical reactivity. Second, the resonance is located at a magnetic field where two open channels become nearly degenerate. This implies the intermediate complex predominantly decays to the second open channel. We describe the resonant loss feature using a model with coupled modes which is analogous to a Fabry-Pérot cavity. Our observations prove the existence of long-lived coherent intermediate complexes even in systems without reaction barriers and open up the possibility of coherent control of chemical reactions.

References in corpus (20)

• A High Phase-Space-Density Gas of Polar Molecules
• Ultracold Dipolar Gas of Fermionic ${}^{23}$Na${}^{40}$K Molecules in their Absolute Ground State
• Quantum Gas of Deeply Bound Ground State Molecules
• Observation of an Efimov-like resonance in ultracold atom-dimer scattering
• Coherent optical transfer of Feshbach molecules to a lower vibrational state
• Evaporation of microwave-shielded polar molecules to quantum degeneracy
• Resonant collisional shielding of reactive molecules using electric fields
• Loss of ultracold RbCs molecules via optical excitation of long-lived two-body collision complexes
• Bimolecular chemistry in the ultracold regime
• Collisions of ultracold molecules in bright and dark optical dipole traps
• Control of reactive collisions by quantum interference
• Probing photoinduced two-body loss of ultracold non-reactive bosonic ${}^{23}$Na${}^{87}$Rb and ${}^{23}$Na${}^{39}$K molecules
• Magnetic Feshbach resonances in collisions of ${}^{23}$Na${}^{40}$K with ${}^{40}$K
• Resonant atom-dimer collisions in cesium: Testing universality at positive scattering lengths
• Ab initio properties of the NaLi molecule in the $a^3{\Sigma }^{+}$ electronic state
• Quantum spin state selectivity and magnetic tuning of ultracold chemical reactions of triplet alkali-metal dimers with alkali-metal atoms
• Steering ultracold reactions through long-lived transient intermediates
• Reactive collisions in confined geometries
• Observation of Microwave Shielding of Ultracold Molecules
• Molecule-molecule and atom-molecule collisions with ultracold RbCs molecules

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• Hyperfine-to-rotational energy transfer in ultracold atom-molecule collisions
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• Multiple polaron quasiparticles with dipolar fermions in a bilayer geometry
• Observation of modulation-induced Feshbach resonance
• Rigorous quantum calculations for atom-molecule chemical reactions in electric fields: from single to multiple partial wave regimes
• Automated Graph-Based Detection of Quantum Control Schemes: Application to Molecular Laser Cooling
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• Molecular resonance identification in complex absorbing potentials via integrated quantum computing and high-throughput computing