Non-adiabatic decay of Rydberg-atom-ion molecules

TL;DR

This study investigates the non-adiabatic decay mechanisms of Rydberg-atom-ion molecules using numerical simulations, revealing that their lifetimes often surpass radiative decay times and depend on vibrational states and quantum interference effects.

Contribution

It provides the first detailed numerical analysis of non-adiabatic lifetimes in RAIMs, highlighting trends and irregularities related to vibrational and Rydberg states.

Findings

Non-adiabatic lifetimes generally exceed radiative lifetimes.

Lifetimes depend on vibrational quantum number and Rydberg state.

Quantum interference causes irregularities in lifetime trends.

Abstract

The decay of Rydberg-atom-ion molecules (RAIMs) due to non-adiabatic couplings between electronic potential energy surfaces is investigated. We employ the Born-Huang representation and perform numerical simulations using a Crank-Nicolson algorithm. The non-adiabatic lifetimes of rubidium RAIMs for the lowest ten vibrational states, $\nu$, are computed for selected Rydberg principal quantum numbers, $n$. The non-adiabatic lifetimes are found to generally exceed the radiative Rydberg-atom lifetimes. We observe and explain a trend of the lifetimes as a function of $\nu$ and $n$, and attribute irregularities to quantum interference arising from a shallow potential well in an inner potential surface. Our results will be useful for future spectroscopic studies of RAIMs.