Computation of electromagnetic properties of molecular ensembles

TL;DR

This paper develops a method to compute the electromagnetic response of molecular ensembles using transfer matrices derived from quantum simulations, enabling efficient analysis of complex arrangements and properties like chirality and duality.

Contribution

It introduces T-matrix formulas for electromagnetic properties of molecular ensembles based on quantum mechanical data, applicable to arbitrary arrangements and high multipolar orders.

Findings

Successfully computed T-matrix for a chiral molecule from quantum data.

Demonstrated calculation of chiro-optical properties for molecular arrangements.

Established a link between quantum simulations and electromagnetic response modeling.

Abstract

We establish a link between quantum mechanical molecular simulations and the transfer matrix of a molecule. The transfer matrix (T-matrix) of an object provides a complete description of its electromagnetic response. Once the T-matrices of the individual components of an ensemble are known, the electromagnetic response of the ensemble can be efficiently computed. This holds for arbitrary arrangements of large number of molecules, as well as for periodic arrays. We provide T-matrix based formulas for computing traditional chiro-optical properties like Circular Dichroism and Oriented Circular Dichroism, and also for quantifying electromagnetic duality and electromagnetic chirality, two properties that are fundamentally related to chiral interactions, and also technologically relevant. The formulas are valid for light-matter interactions of arbitrary high multipolar orders. We exemplify our approach by first computing the T-matrix of a cross-like arrangement of four copies of a chiral molecule from the time-dependent Hartree-Fock theory simulation data of the individual molecule, and then computing the aforementioned electromagnetic properties of both the cross and the individual molecule. The link that we establish is a necessary step towards obtaining T-matrix based constitutive relations of general bulk molecular materials from quantum mechanical simulations of their molecular constituents.