49 citations · 82 across the 12 of their papers we have counts for
11 papers · 1 filter
Lattice dynamics of disordered phases of silicon and spatially resolved computations of thermal conductivity
A. Gautam, C. Ugwumadu, L. A. M. Rosset +3
The lattice dynamics of disordered systems (amorphous solids, polymers and glasses) are often distinct from crystalline analogues. Examples include the "two-level systems" and the…
Solver-Agnostic Implementation of Atom-Informed Thermal Conductivity Fields in Continuum Heat-Flow Simulations
W. Downs, C. Ugwumadu, M. Ali +1
A recent work introduced the Simulator Collection for Atomic-to-Continuum Scales (SCACS) toolkit, a framework for improving finite element predictions of heat flow by mapping atom-…
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…
Seamlessly joining length scales: From atomistic thermal graphs to anisotropic continuum conductivity
C. Ugwumadu, D. A. Drabold, R. M. Tutchton
Thermal transport in complex solids is governed by local structure, defects, and anisotropy, yet most continuum models still rely on oversimplified, homogenized conductivities. Her…
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…
Gaunt and Breit Two-electron contributions to Mean-field Transformations and Fine Structure Splitting
Luca Murg, Christopher Lane, Roxanne M. Tutchton
Materials utilized by novel energy systems are often studied using weakly correlated mean-field theories. However, if these systems incorporate heavy elements, relativistic effects…
Atomistic modeling of uranium monocarbide with a machine learning interatomic potential
Lorena Alzate-Vargas, Kashi N. Subedi, Roxanne M. Tutchton +3
Uranium monocarbide (UC) is an advanced ceramic fuel candidate due to its superior uranium density and thermal conductivity compared to traditional fuels. To accurately model UC at…
Effects of Galactic Irradiation on Thermal and Electronic Transport in Tungsten
C. Ugwumadu, D. A. Drabold, R. Tutchton
The impact of irradiation on the thermal and electronic properties of materials is a persistent puzzle, particularly defect formation at the atomic and nanoscales. This work examin…
Toward machine learning interatomic potentials for modeling uranium mononitride
Lorena Alzate-Vargas, Kashi N. Subedi, Nicholas Lubbers +4
Uranium mononitride (UN) is a promising accident-tolerant fuel because of its high fissile density and high thermal conductivity. In this study, we developed the first machine lear…
Direct Observation of Coherent Longitudinal and Shear Acoustic Phonons in TaAs Using Ultrafast X-ray Diffraction
Min-Cheol Lee, N. Sirica, S. W. Teitelbaum +18
Using femtosecond time-resolved X-ray diffraction, we investigated optically excited coherent acoustic phonons in the Weyl semimetal TaAs. The low symmetry of the (112) surface pro…
Coherent Helicity-Dependent Spin-Phonon Oscillations in the Ferromagnetic van der Waals Crystal CrI3
P. Padmanabhan, F. L. Buessen, R. Tutchton +9
The discovery of two-dimensional (2D) systems hosting intrinsic long-range magnetic order represents a seminal addition to the rich physical landscape of van der Waals (vdW) materi…