# A Green's function approach to giant-dipole systems

## TL;DR

This paper develops a Green's function framework to analyze giant-dipole atomic and molecular systems in crossed electric and magnetic fields, providing new insights into their polarizability and potential energy surfaces.

## Contribution

It introduces a Green's function method for giant-dipole states, including derivations, comparisons with exact methods, and a regularized Green's function representation.

## Key findings

- Derived Green's functions for giant-dipole systems.
- Compared Green's function approach with exact diagonalization.
- Identified divergence issues in Fermi-pseudopotential methods.

## Abstract

In this work we perform a Green's function analysis of giant-dipole systems. First we derive the Green's functions of different magnetically field-dressed systems, in particular of electronically highly excited atomic species in crossed electric and magnetic fields, so-called giant-dipole states. We determine the dynamical polarizability of atomic giant-dipole states as well as the adiabatic potential energy surfaces of giant-dipole molecules in the framework of the Green's function approach. Furthermore, we perform an comparative analysis of the latter to and exact diagonalization scheme and show the general divergence behavior of the widely applied Fermi-pseudopotential approach. Finally, we derive the giant-dipole's regularized Green's function representation.