QD4ICEC

Full quantum dynamics of the interparticle Coulombic electron capture

01/01/2023 to 31/12/2025

Inter-particle Coulombic electron capture (ICEC) is a recently discovered environment-enabled electron capture process by means of which a free electron can be efficiently attached to a system (i.e. ion, atom, molecule, or quantum dot). The excess electron attachment energy is simultaneously transferred to a neighboring system which undergoes ionization. ICEC has been predicted theoretically in van-der- Waals and hydrogen bonded systems as well as in quantum dot arrays. The theoretical approaches employed in these works range from analytical models to ab-initio electronic structure and dynamical calculations. A common assumption in these approaches is that nuclei remain fixed during ICEC. However, based on observations on the related inter-particle Coulombic decay (ICD), nuclear dynamics should play an important role changing the efficiency and/or influencing the final state of the system. The aim of our project is therefore to develop, implement, and apply original quantum-dynamical methods to provide a complete description of ICEC. To achieve this ambitious goal, we will combine the complementary expertise of our groups: we will develop ICEC models that will be (numerically) exactly solved using the multiconfiguration time-dependent Hartree (MCTDH) method. We will gradually lower the degree of approximation in such model systems, thus enabling the study of realistic atomic and molecular systems. Furthermore, we will develop analytical approaches which will provide insights into the impact of nuclear dynamics in ICEC and help the interpretation of the numerical simulations. Finally, the information gathered through these validated methods will lead to the development of efficient tools based on the R-matrix approach.
Owing to the ubiquity of electron capture processes, our project will have a significant impact in a broad range of applications from radiation damage, to astro-chemistry/physics. Furthermore, our results will lay the groundwork for the interpretation of expected, near-future experiments on ICEC and at the same time, stimulating a theory-experiment synergy for the prediction of promising ICEC target systems.