Quantum transport in graphene nanoribbon networks: complexity reduction by a network decimation algorithm

Abstract

We study electronic quantum transport (QT) in graphene nanoribbon (GNR) networks on mesoscopic length scales. We focus on zigzag GNRs and investigate the conductance properties of statistical networks. To this end we use a density-functional-based tight-binding model to determine the electronic structure and QT theory to calculate electronic transport properties. We then introduce a new efficient network decimation algorithm that reduces the complexity in generic three-dimensional GNR networks. We compare our results to semi-classical calculations based on the nodal analysis (NA) approach and discuss the dependence of the conductance on network density and network size. We show that a NA model cannot reproduce the QT results nor their dependence on model parameters well. Thus, solving the quantum network by our efficient approach is mandatory for accurate modelling the electron transport through GNR networks.

Keywords

• graphene nanoribbon (GNR)
• network
• density-functional-based tight binding (DFTB)
• quantum transport
• recursive Green’s function formalism (RGF)
• decimation scheme