GRANAD - Simulating GRAphene nanoflakes with ADatoms

Published

August 26, 2025

Author(s)

David Dams, Miriam Kosik, Marvin Muller, Abhishek Ghosh, Antton Babaze, Julia Szczuczko, Garnett Bryant, Andres Ayuela, Carsten Rockstuhl, Marta Pelc, Karolina Slowik

Abstract

GRANAD is a new program based on the tight-binding approximation to simulate optoelectronic properties of graphene nanoflakes and Su–Schrieffer–Heeger (SSH) chains with possible adatom defects under electromagnetic illumination. Its core feature is the numerical solution of a time-domain master equation for the spin-traced one-particle reduced density matrix. It offers direct time-resolved insights into the evolution of charge distribution, access to induced field dynamics, and characteristics of the plasmonic response. Other computable quantities include energy profiles, electron distribution in real space, and absorption spectra. GRANAD is written in Python and relies on the JAX library for high-performance array computing, just-in-time compilation, and differentiability. It is intended to be lightweight, portable, and easy to set up, offering a transparent and efficient way to access the properties of low-dimensional carbon structures from the nanoscale to the mesoscopic regime. GRANAD is open source, with the full code and documentation available at https://github.com/GRANADlauncher/granad.git.

Citation

Computer Physics Communications

Volume

317

Pub Type

Journals

Download Paper

https://doi.org/10.1016/j.cpc.2025.109818

Local Download

Keywords

Simulations, graphene, Su-Schrieffer-Heeger model, time-domain master equation

Citation

Dams, D. , Kosik, M. , Muller, M. , Ghosh, A. , Babaze, A. , Szczuczko, J. , Bryant, G. , Ayuela, A. , Rockstuhl, C. , Pelc, M. and Slowik, K. (2025), GRANAD - Simulating GRAphene nanoflakes with ADatoms, Computer Physics Communications, [online], https://doi.org/10.1016/j.cpc.2025.109818, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=957737 (Accessed October 16, 2025)