MSE Talk: Ashwin Ramasubramaniam

Speaker: Ashwin Ramasubramaniam, University of Massachusetts Amherst

Title: Predictive modeling of optoelectronic properties of layered materials via non-empirical hybrid density functionals

Abstract: Van der Waals layered materials and their 2D derivatives are of significant interest across a range of fields such as nanoscale electronics, quantum computing, energy storage, and catalysis, to name a few. Such technological interest brings with it the need – and, correspondingly, challenges – for quantitatively-accurate, predictive models of these materials. I will discuss our recent work on the development of screened-range separated hybrid functionals for first-principles modeling of layered materials. Specifically, I will focus on a few prototypical van der Waals layered materials and demonstrate how highly-accurate density functionals can be designed systematically and non-empirically to produce electronic bandstructures and optical absorption spectra that are as accurate as those arising from computationally-intensive many-body perturbation theory approaches. I will also briefly discuss ongoing work along these lines for layered magnetic semiconductors.

Bio: Ashwin Ramasubramaniam is a Professor in the Department of Mechanical & Industrial Engineering at the University of Massachusetts Amherst and the Director of the Materials Science & Engineering Graduate Program. He received his Ph.D. in the Mechanics of Solids and Structures from Brown University in 2005. Prior to joining the UMass Amherst faculty in 2009, he was a Research Associate in Applied & Computational Mathematics at Princeton University and a Postdoctoral Scholar in Aeronautical Engineering at Caltech. His research interests are at the intersection of materials physics, chemistry, and mechanics. Examples of recent work include modeling optoelectronic properties of layered magnets, intercalated vdW materials, hybrid organic–inorganic materials, and EPR/ESR response of 2D electrocatalysts.