Real-Space Mapping of Electronic Conductivity in Complex Materials

Abstract

We introduce KuboMap, a real-space representation of electronic conductivity derived from the Kubo-Greenwood formula. KuboMap defines a nonnegative conductivity density whose spatial integral recovers the total conductivity and whose form is guided by Mott's picture of transport through spatially overlapping electronic states. This construction provides a direct map of the transport-active regions of a material. Applied to aluminum, KuboMap recovers an extended metallic conduction network. Applied to amorphous silicon, it distinguishes an insulating defect-free network from a defective structure in which localized near-Fermi states form connected hopping-like pathways. In silicon-oxides, it captures the loss of conduction as increasing oxygen content disrupts Silicon-rich transport networks. KuboMap provides a physically transparent route from Kubo--Greenwood conductivity to real-space transport pathways in complex materials.