Argonne National Laboratory

Out-of-Equilibrium Optical and Quantum Materials Simulations

Out-of-Equilibrium Optical and Quantum Materials Simulations

A variety of theoretical approaches, ranging from computational electrodynamics to advanced electronic structure theory methods are applied to understand the optoelectronic properties of nanoscale materials in- and out-of equilibrium, as well as their interactions with photons, plasmons, electrons and phonons.

Optical and quantum materials such as plasmonic materials, 2D materials and quantum defects are of much current interest owing to potential applications in opto-electronics, quantum information and sensing. We have a variety of capabilities for simulating the responses of these materials.

Optical interactions with nanoscale materials, including plasmonic materials and hybrid systems involving quantum dots are described with computational electrodynamics methods including Lumerical, MEEP, and home-grown Finite-Difference Time-Domain (FDTD) approaches. 

In addition, we pursue more explicitly quantum mechanical approaches, including quantum density matrix simulations that also allow for environmental interactions, such as quantum dots and other potential qubits (e.g., NV centers) interacting with light and plasmonic or mechanical resonators.

Electron transport properties of nanostructures are simulated using the Landauer approach and non-equlibrium Green’s functions techniques (SIESTA/TransSIESTA). Such calculations make extensive use of self-energy corrections based on the GW approach (BerkeleyGW, West).

Current-driven, non-equilibrium phonon dynamics are described using the Boltzmann transport framework (home-grown code) parametrized using density-functional theory based calculations: Migdal approximation for electron-phonon interactions (EPW) and finite-differences for phonon-phonon interactions.