Open positions:

  • Ph.D. Project in Physics and Astronomy: Statistical models for plasticity in amorphous solids

    How does an amorphous solid flow? In contrast to crystalline materials, where plastic flow can be ascribed to dislocation motion, our understanding of deformation and flow in disordered matter (glassy metals and polymers, many soft materials such as foams, emulsions, colloidal matter, and assemblies of living cells) is much less developed and still based on very phenomenological models. This project aims to develop a statistical framework for describing yield and plastic deformation in amorphous systems. We use molecular dynamics on the particle scale to investigate the fundamental physics, and attempt to link it quantitatively to mescoscopic methods that coarse-grain the atomistic dynamics into a nonlocal continuum description. The PhD student will develop both methods side by side and apply them to better understand the fundamental nature of the yielding transition in the athermal limit, the role of mechanical noise in activating plastic events, and localization phenomena in confined geometries.

    References:
    Nicolas A, Barrat J-L, Rottler J. "Effects of Inertia on the Steady-Shear Rheology of Disordered Solids." Physical Review Letters. 2016;116:058303.
    Nicolas A, Rottler J, Barrat J-L. "Spatiotemporal correlations between plastic events in the shear flow of athermal amorphous solids." The European Physical Journal E. 2014;37:1-11

  • Ph.D. Project in Physics and Materials Engineering: Interface properties from atomistic simulations

    We seek a PhD student with an interest in computational condensed matter physics. The primary goal of this project will be to use ab-initio methods (Density Functional Theory) based techniques to study the properties of interfaces in complex materials. Of particular interest will be solid/solid interfaces in the form of grain boundaries in ferrous or titanium-based alloys, but other systems may be studied as well. The candidate can build upon and expand on a multiscale QM/MM method recently developed in our group. The project will be jointly supervised by Prof. Joerg Rottler and Prof. Matthias Militzer (Materials Engineering)

    References:
    L. Huber et al, 
    A QM/MM approach for low-symmetry defects in metals, Computational Materials Science 118, 259 (2016)



  • Ph.D. Project in Materials Engineering & Physics: Developing a new simulation method for linking atomic scale effects to diffusion processes

    We are seeking a Ph.D. student to develop and apply a new hybrid computational approach for the simulation of solute redistribution in complex alloys. The project builds on previous work at UBC that  provides insight into the physics of solute diffusion due to the presence of atomistic, crystalline defects and the resulting structural changes in the material.  This technique treats the atomistic topology of a crystalline material by density fields and evolves the alloy composition based on an approximated atomistic free energy functional and continuum description of mass transport. As a result, we can study diffusion processes that are inaccessible with particle based molecular dynamics simulations but retain crucial aspects of the discrete nature of matter.

    We want to further explore the potential of this technique and to improve both its thermodynamic and kinetic descriptions, allowing (for example) an extension to interstitial alloys.  Applications of the resulting model to the problems of defect induced precipitation/phase separation, grain boundary/solute interaction are envisioned. The ideal candidate for this position will have a background in condensed matter physics and/or materials science/engineering with some experience with atomistic simulation (molecular dynamics, Monte Carlo, phase field (crystal) or classical density functional theory) and good computational skills (e.g. C++, python). The project will be jointly supervised with Prof. Chad Sinclair, Materials Engineering.

    References:
    E. Dontsova, J. Rottler, and C. W. Sinclair, Phys. Rev. B 90, 174102 (2014)
    E. Dontsova, J. Rottler, and C. W. Sinclair, Phys. Rev. B 91, 224103 (2015)