Exploring and controlling inelastic and reactive collisions on the quantum level is a main goal of the developing field of ultracold chemistry. For this, the preparation of precisely defined initial atomic and molecular states in tailored environments is necessary. Here we present experimental studies of inelastic collisions of metastable ultracold Rb molecules in an array of quasi-1D potential tubes. In particular, we investigate collisions of molecules in the absolute lowest triplet energy level where any inelastic process requires a change of the electronic state. Remarkably, we find similar decay rates as for collisions between rotationally or vibrationally excited triplet molecules where other decay paths are also available. The decay rates are close to the ones for universal reactions but vary considerably when confinement and collision energy are changed. This might be exploited to control the collisional properties of molecules.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5376650 | PMC |
| http://dx.doi.org/10.1038/ncomms14854 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Electronically Nonadiabatic Quenching of Excited States of O by Collisions with O Atoms.
J Phys Chem A
January 2025
Department of Chemistry and Chemical Biology, Center for Computational Chemistry, University of New Mexico, Albuquerque, New Mexico 87131, United States.
The kinetics of electronically inelastic quenching of O(Δ) and O(Σ) by collisions with O(P) have been investigated using mixed quantum-classical trajectories governed by adiabatic potential energy surfaces and state couplings generated from a recently developed diabatic potential energy matrix (DPEM) for the 14 lowest-energy A' states of O. Using the coherent switching with decay of mixing (CSDM) method, dynamics calculations were performed both with 14 coupled electronic states and with 8 coupled electronical states, and similar results were obtained. The calculated thermal quenching rate coefficients are generally small, but they increase with temperature.
View Article and Find Full Text PDFElectronic quenching of sulfur induced by argon collisions.
Phys Chem Chem Phys
January 2025
Univ Rennes, CNRS, IPR (Institut de Physique de Rennes) - UMR 6251, F-35000 Rennes, France.
An accurate potential energy model, explicitly designed for studying scattering and treating the spin-orbit and nonadiabatic couplings on an equal footing, is proposed for the S + Ar system. The model is based on the Effective Relativistic Coupling by Asymptotic Representation (ERCAR) approach, building the geometry dependence of the spin-orbit interaction a diabatisation scheme. The resulting full diabatic model is used in close-coupling calculations to compute inelastic scattering cross sections for de-excitation from the S(D) fine structure level into the P multiplet.
View Article and Find Full Text PDFAccurate machine learning of rate coefficients for state-to-state transitions in molecular collisions.
J Chem Phys
January 2025
Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada.
We present an algorithm that combines quantum scattering calculations with probabilistic machine-learning models to predict quantum dynamics rate coefficients for a large number of state-to-state transitions in molecule-molecule collisions much faster than with direct solutions of the Schrödinger equation. By utilizing the predictive power of Gaussian process regression with kernels, optimized to make accurate predictions outside of the input parameter space, the present strategy reduces the computational cost by about 75%, with an accuracy within 5%. Our method uses temperature dependences of rate coefficients for transitions from the isolated states of initial rotational angular momentum j, determined via explicit calculations, to predict the temperature dependences of rate coefficients for other values of j.
View Article and Find Full Text PDFState-to-state scattering of highly vibrationally excited NO with argon at collision energies over 1 eV.
Phys Chem Chem Phys
January 2025
Department of Chemistry, University of Missouri, Columbia, MO 65211, USA.
We present state-to-state differential cross sections for rotationally inelastic collisions of vibrationally excited NO XΠ ( = 9) with Ar using a near-counterpropagating molecular beam geometry. These were obtained using the stimulated emission pumping technique coupled with velocity map imaging. Collision energies well over ∼1 eV were achieved and rotational excitations up to ∼Δ = 60 recorded for the first time for inelastic collisions.
View Article and Find Full Text PDFStudy of the N2 vibrational relaxation behaviors via the CO rovibrational thermometry.
J Chem Phys
December 2024
Deep Space Exploration Laboratory/Department of Modern Mechanics, University of Science and Technology of China, Hefei 230026, People's Republic of China.
This paper performed a comprehensive study of the thermal nonequilibrium effects of CO/Ar mixtures with various degrees of N2 additions and probed the N2 relaxation behaviors via the CO rovibrational thermometry. The rovibrational temperature time histories of shock-heated CO/N2/Ar mixtures were measured via a laser-absorption technique, and the corresponding vibrational relaxation data were summarized at 1890-3490 K. The measured results were compared with predictions from the Schwartz-Slawsky-Herzfeld (SSH) formula and the state-to-state (StS) approach (treating CO and N2 as pseudo-species).
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!