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Measurement of Ultrafast Vibrational Coherences in Polyatomic Radical Cations with Strong-Field Adiabatic Ionization
Published on: August 6, 2018
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A Feshbach resonance in collisions between triplet ground-state molecules
Juliana J Park1, Yu-Kun Lu2, Alan O Jamison3,4
1MIT-Harvard Center for Ultracold Atoms, Research Laboratory of Electronics, Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA. jjpark@mit.edu.
Nature
|February 1, 2023
Summary
Researchers observed a significant Feshbach resonance in collisions between ultracold ground-state NaLi molecules. This finding demonstrates long-lived molecular complexes and opens new avenues for controlling chemical reactions.
Area of Science:
- Ultracold molecular physics
- Quantum chemistry
- Quantum simulation
Background:
- Collisional resonances are crucial for manipulating interactions in ultracold gases.
- Previous studies focused on atom-atom and atom-molecule collisions, with limited evidence for ground-state molecules.
- The existence of resonances in ultracold ground-state molecules was debated due to potential state density and decay issues.
Purpose of the Study:
- To investigate the existence of Feshbach resonances in collisions between ultracold ground-state molecules.
- To characterize the properties and implications of such molecular Feshbach resonances.
- To explore the potential for coherent control of chemical reactions using these resonances.
Main Methods:
- Experimental observation of Feshbach resonances in collisions of triplet ground-state NaLi molecules.
- Measurement of collisional loss rates and magnetic field characteristics.
- Modeling the resonant loss feature using a coupled-mode approach analogous to a Fabry-Pérot cavity.
Main Results:
- A pronounced and narrow Feshbach resonance (25 mG) was observed in NaLi molecule collisions.
- Collisional loss rates were enhanced by over two orders of magnitude, indicating strong chemical reactivity.
- The resonance occurred at a magnetic field with nearly degenerate open channels, leading to decay in the second channel.
Conclusions:
- The study provides strong evidence for long-lived coherent intermediate complexes in ultracold ground-state molecule collisions.
- These findings challenge previous assumptions about the stability of resonant complexes in such systems.
- The discovery opens possibilities for coherent control of chemical reactions in ultracold molecular systems.
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