Intermolecular forces and correlations mediated by a phonon bath
| Autor: | Richard Schmidt, Enderalp Yakaboylu, Andreas Deuchert, G. Bighin, Xiang Li, Mikhail Lemeshko |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Phonon
Atomic Physics (physics.atom-ph) General Physics and Astronomy FOS: Physical sciences 010402 general chemistry 01 natural sciences Molecular physics Physics - Atomic Physics Physics - Chemical Physics 0103 physical sciences Mesoscale and Nanoscale Physics (cond-mat.mes-hall) Physics - Atomic and Molecular Clusters Physical and Theoretical Chemistry Ansatz Physics Chemical Physics (physics.chem-ph) Bipolaron Condensed Matter - Mesoscale and Nanoscale Physics 010304 chemical physics Intermolecular force Observable Diatomic molecule 0104 chemical sciences Quantum Gases (cond-mat.quant-gas) Quasiparticle Condensed Matter - Quantum Gases Ground state Atomic and Molecular Clusters (physics.atm-clus) |
| Zdroj: | The Journal of Chemical Physics |
| DOI: | 10.1063/1.5144759 |
| Popis: | Inspired by the possibility to experimentally manipulate and enhance chemical reactivity in helium nanodroplets, we investigate the effective interaction and the resulting correlations between two diatomic molecules immersed in a bath of bosons. By analogy with the bipolaron, we introduce the \emph{biangulon} quasiparticle describing two rotating molecules that align with respect to each other due to the effective attractive interaction mediated by the excitations of the bath. We study this system in different parameter regimes and apply several theoretical approaches to describe its properties. Using a Born-Oppenheimer approximation, we investigate the dependence of the effective intermolecular interaction on the rotational state of the two molecules. In the strong-coupling regime, a product-state ansatz shows that the molecules tend to have a strong alignment in the ground state. To investigate the system in the weak-coupling regime, we apply a one-phonon excitation variational ansatz, which allows us to access the energy spectrum. In comparison to the angulon quasiparticle, the biangulon shows shifted angulon instabilities and an additional spectral instability, where resonant angular momentum transfer between the molecules and the bath takes place. These features are proposed as an experimentally observable signature for the formation of the biangulon quasiparticle. Finally, by using products of single angulon and bare impurity wave functions as basis states, we introduce a diagonalization scheme that allows us to describe the transition from two separated angulons to a biangulon as a function of the distance between the two molecules. Comment: 14 pages, 8 figures |
| Databáze: | OpenAIRE |
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