Numerical studies of the interaction of an atomic sample with the electromagnetic field in two dimensions

Abstract

We consider the interaction of electromagnetic radiation of arbitrary polarization with multilevel atoms in a self-consistent manner, taking into account both spatial and temporal dependencies of local fields. This is done by numerically solving the corresponding system of coupled Maxwell-Liouville equations for various geometries. In particular, we scrutinize linear optical properties of nanoscale atomic clusters, demonstrating the significant role played by collective effects and dephasing. It is shown that subwavelength atomic clusters exhibit two resonant modes, one of which is localized slightly below the atomic transition frequency of an individual atom, while the other is positioned considerably above it. As an initial exploration of future applications of this approach, the optical response of core-shell nanostructures, with a core consisting of silver and a shell composed of resonant atoms, is examined.

Quantum emitter dipole–dipole interactions in nanoplasmonic systems

“…The Hamiltonian (1), due to all the simplifications made, describes a closed system without any coupling to a probing field. We have shown, however, that the dark states are characterized by very low expectation value of the observable P defined by equation (11).…”

“…Approaches different from ours have been developed to model the behaviour of the nanoplasmonic systems in question. Among the notable ones are the methods based on finite-difference time-domain (FDTD) solution of Maxwell-Liuville equations [11] and quantum multiple-scattering methods based on macroscopic quantum electrodynamics [12], which have their advantages and disadvantages. Most notably, they account for the ohmic losses inside the metal and the consequent line broadening which are significant in the plasmonic systems.…”

First-principles simulation of light propagation and exciton dynamics in metal cluster nanostructures

“…alteration of the number of atoms in a cluster or even their spatial configuration leads to dramatic changes of their optical and chemical properties [3,5,[35][36][37][38][39]. In order to describe the interaction of these ultra-small clusters with electric fields, the well-developed theoretical approaches mentioned above were coupled to quantum chemistry to account for the intrinsically quantum nature of the clusters [40][41][42][43]. At the moment the attention of researchers is mainly devoted to model few-energy-level systems with degenerate electronic excited states, while for the development of novel plasmonic systems and for the interpretation of experimental results the realistic description of the electronic structure of a single constituent as well as of the aggregate as a whole is mandatory.…”

Molecular spectra in collective Dicke states

“…Both the position and width of the peak are modified in a system of N TLSs, see for example related studies involving plasmons or polaritons [21,22]. Here, we will identify the role of interactions and pinpoint how these effects in the emission spectrum scale with N .…”