Favoritism of quantum dot inter-Coulombic decay over direct and multi-photon ionization by laser strength and focus

Modeling Intermolecular Coulombic Decay with Non-Hermitian Real-Time Time-Dependent Density Functional Theory

In this work, we investigate the capability of using real-time time-dependent density functional theory (RT-TDDFT) in conjunction with a complex absorbing potential (CAP) to simulate the intermolecular Coulombic decay (ICD) processes following the ionization of an inner-valence electron. We examine the ICD dynamics in a series of noncovalent bonded dimer systems, including hydrogen-bonded and purely van der Waals (VdW)-bonded systems. In comparison to previous work, we show that RT-TDDFT simulations with a CAP correctly capture the ICD phenomenon in systems exhibiting a stronger binding energy. The calculated time scales for ICD of the studied systems are in the range of 5-50 fs, in agreement with previous studies. However, there is a breakdown in the accuracy of the methodology for the pure VdW-bonded systems. Overall, the presented RT-TDDFT/CAP methodology provides a powerful tool for differentiating between competing electronic relaxation pathways following inner-valence or core ionization without necessitating any a priori assumptions.

Interatomic and Intermolecular Coulombic Decay

Interatomic or intermolecular Coulombic decay (ICD) is a nonlocal electronic decay mechanism occurring in weakly bound matter. In an ICD process, energy released by electronic relaxation of an excited atom or molecule leads to ionization of a neighboring one via Coulombic electron interactions. ICD has been predicted theoretically in the mid nineties of the last century, and its existence has been confirmed experimentally approximately ten years later. Since then, a number of fundamental and applied aspects have been studied in this quickly growing field of research. This review provides an introduction to ICD and draws the connection to related energy transfer and ionization processes. The theoretical approaches for the description of ICD as well as the experimental techniques developed and employed for its investigation are described. The existing body of literature on experimental and theoretical studies of ICD processes in different atomic and molecular systems is reviewed.

Wavepacket golden rule treatment of interparticle Coulombic decay in paired quantum dots

The interparticle Coulombic decay process in paired quantum dots is studied by electron dynamics calculations. We consider a pair of Coulomb-coupled one-electron charged gallium arsenide quantum dots embedded in a nanowire. The two-electron decay process is approximately described by a single active electron model. Within this model, we employ the time-dependent wavepacket approach to the Fermi golden rule (introduced in the context of vibrational predissociation) to calculate autoionization rates, which are compared to exact rates obtained from fully correlated two-electron dynamics calculations. We found that the approximate decay rates agree well with the exact results in the limit of sufficiently separated quantum dots. Finally, we explore whether the short-range behavior of the new model can be further enhanced by the inclusion of local exchange effects by means of regularization of the Coulomb-potential based on a Jastrow-Slater wavefunction. The proposed method may open a route to study the interparticle Coulombic decay in more intricate systems, e.g., paired metal-nanoparticle-quantum dot systems.