7 papers
Real-Space Mapping of Electronic Conductivity in Complex Materials
C. Ugwumadu, D. A. Drabold, R. M. Tutchton
We introduce KuboMap, a real-space representation of electronic conductivity derived from the Kubo-Greenwood formula. KuboMap defines a nonnegative conductivity density whose spati…
A Defect-Free Model of Amorphous Silicon with Pristine Electronic Structure
Louise A. M. Rosset, Chinonso Ugwumadu, Stephen R. Elliott +2
Amorphous silicon (a-Si) is understood to be the canonical continuous random network material, ideally defined by fully fourfold coordination. Here, we show that a defect-free ('id…
Temperature dependence of electronic conductivity from ab initio thermal simulation
Ridwan Hussein, Chinonso Ugwumadu, Kishor Nepal +3
We present a temperature-dependent extension of the approximate electronic conductivity formula of Hindley and Mott that leverages time-averaged fluctuations of the electronic dens…
Electronic and thermal properties of the phase-change memory material, Ge2Sb2Te5, and results from spatially resolved transport calculations
Kishor Nepal, Aashish Gautam, Ridwan Hussein +4
We report new insights into the electronic, structural, and transport (heat and charge) properties of the phase-change memory material Ge2Sb2Te5. Using realistic structural models…
New models of clean and hydrogenated amorphous silicon surfaces
Kishor Nepal, Aashish Gautam, Chinonso Ugwumadu +1
We present new atomistic models of amorphous silicon (a-Si) and hydrogenated amorphous silicon (a-Si:H) surfaces. The a-Si model included 4096 atoms and was obtained using local or…
Spatially Local Estimates of the Thermal Conductivity of Materials
C. Ugwumadu, A. Gautam, Y. G. Lee +1
In this paper we describe a spatial decomposition of the thermal conductivity, what we name "site-projected thermal conductivity", a gauge of the thermal conduction activity at eac…