Non-adiabatic quantum interference in the ultracold Li + LiNa → Li2 + Na reaction

Electronically non-adiabatic effects play an important role in many chemical reactions. However, how these effects manifest in cold and ultracold chemistry remains largely unexplored. Here for the first time we present from first principles the non-adiabatic quantum dynamics of the reactive scatteri...

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Bibliographic Details
Published in:Physical chemistry chemical physics : PCCP 2021-01, Vol.23 (9), p.5096-5112
Main Authors: Kendrick, Brian K, Li, Hui, Li, Ming, Kotochigova, Svetlana, Croft, James F E, Balakrishnan, Naduvalath
Format: Article
Language:English
Subjects:
Adiabatic flow
Alkali metals
Chemical reactions
cold molecules
Couplings
Dimers
Dynamics
Electron states
First principles
Inorganic and physical chemistry
INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
Interference
Lithium
Molecular machines
non-adiabatic
Poisson distribution
Potential energy
quantum dynamics
Quantum interference effects
Statistical analysis
ultracold chemistry
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Summary:Electronically non-adiabatic effects play an important role in many chemical reactions. However, how these effects manifest in cold and ultracold chemistry remains largely unexplored. Here for the first time we present from first principles the non-adiabatic quantum dynamics of the reactive scattering between ultracold alkali-metal LiNa molecules and Li atoms. We show that non-adiabatic dynamics induces quantum interference effects that dramatically alter the ultracold rotationally resolved reaction rate coefficients. The interference effect arises from the conical intersection between the ground and an excited electronic state that is energetically accessible even for ultracold collisions. These unique interference effects might be exploited for quantum control applications such as a quantum molecular switch. The non-adiabatic dynamics are based on full-dimensional ab initio potential energy surfaces for the two electronic states that includes the non-adiabatic couplings and an accurate treatment of the long-range interactions. A statistical analysis of rotational populations of the Li2 product reveals a Poisson distribution implying the underlying classical dynamics are chaotic. The Poisson distribution is robust and amenable to experimental verification and appears to be a universal property of ultracold reactions involving alkali metal dimers.
ISSN:1463-9076
1463-9084
DOI:10.1039/d0cp05499b