# Tomás Arias

## Professor, Stephen H. Weiss Presidential Fellow

### Overview

Linking the ab initio quantum mechanical description of materials to the physical behavior of real materials, involving identification of problems where the quantum perspective can make a significant impact, exploitation of theoretical techniques and supercomputer architectures to carry out large scale quantum calculations, and development of new theoretical techniques to link ab initio calculations with phenomena on larger scales. Current application areas include mechanical properties of nanoscale systems including carbon nanotubes, fundamental processes involved in crystal growth, quantum mechanics of systems in contact with a solution, physics of novel solar cell systems

### Research Focus

The focus of our research group is to calculate ab initio (from first principles) how the rich variety of complex phenomena in condensed matter systems arises from the well-understood, simple underlying interactions among electrons and nuclei. This work is multi-faceted and involves developing understanding of interacting many-body systems, unraveling physics spanning wide ranges of length- and time- scales, and learning how to describe thermal effects occurring in phase spaces with complex topologies. Answering the questions which underlie these issues requires work in a broad range of disciplines including mathematics, numerical analysis, software development and supercomputer architecture, many-body theory, and condensed matter physics. My students contribute to a rich mix of applications and more far-reaching theoretical problems of their own choice according to their tastes and talents. Our students generally publish three to four papers before graduation.

Current topics of interest include development of wavelet and excited-state methods for electronic structrure calculations, phonon-phonon couplings in one-dimensional systems (carbon nantubes), internal friction in materials, interaction of carbon nanotubes with surfaces, surface chemistry, organic solar cells, photoelectrochemical cells, and development of new fundamental descriptions of the interaction of water with quantum systems.

**Graduate Students**

Katie Schwartz, Akif Ozhabes and Michelle Kelley

## In the news

- Physics theory could be slam dunk for basketball coaches
- Energy center receives $12.6 million in renewed funding
- Cornell team develops more efficient photocathode
- Physics theory used to predict crowd behavior
- $10.75M grant aids next-gen fuel cell development
- Six faculty honored with Weiss teaching awards