Steve and Judy's travel blog: Physics Talk Online 5:30 MDT Thursday

Thursday, July 15, 2021

Physics Talk Online 5:30 MDT Thursday

Who knows what those crazy electrons are going do? One or two at a time and they act just fine. Once they start to run in packs though, look out, anything could happen.

Are there enough electrons that we need to worry about them? This guy says there are more electrons in the atoms of a paper clip than there are stars in the universe, so yeah, I guess it matters what electrons do. We’re all invited to attend tomorrow night as he explains what we think we know about when “many electrons” get together.

Heinz R Pagels Public Lecture

Please join us LIVE ONLINE TOMORROW

Thursday, July 15, 5:30 pm MDT/23:30 UTC

followed by an interactive Q&A

Cyrus Dreyer

Stony Brook University

Understanding Solids with Supercomputers

Many Electrons at a Time

According to visionary American physicist Richard Feynman, the most important concept in all of science is "the atomic hypothesis that all things are made of atoms — little particles that move around in perpetual motion, attracting each other when they are a little distance apart, but repelling upon being squeezed into one another.” The properties of the materials that make up the world around us are governed by how these atoms attract and repel each other, which is determined by interactions between the electrons most loosely-bound to those atoms. For example, whether a solid is hard and translucent like diamond, or soft and opaque like graphite; whether a material conducts electricity and heat like copper, or prevents the flow of electricity and heat like rubber; whether a material can be used in computer chips, like silicon; or whether a drug like aspirin will mitigate a fever.

Understanding these interactions turns out to be a very difficult problem, one that has challenged physicists for a century. For one thing, electrons are small, and thus governed by the weird properties of quantum mechanics. Also, there are a lot of them in a given material: there are more electrons in the atoms that make up a paper clip than there are stars in the universe. In this talk I will describe a particular approach to tackling the “many electron problem”, known as Density Functional Theory, which, combined with the most powerful supercomputers in the world, has revolutionized our ability to describe and predict the properties of materials. I will give a variety of examples of how this knowledge of materials can be used to develop novel electronic devices for modern technology.

Cyrus Dreyer earned a Ph.D. in Materials from the University of California, Santa Barbara, and then was a postdoctoral associate at Rutgers University. He is currently an assistant professor at Stony Brook University in the department of Physics and Astronomy, and an affiliate research scientist at the Flatiron Institute, Center for Computational Quantum Physics. His research interests involve developing and implementing computational techniques based on density functional theory to explore the properties of electronic materials.

Introducer and Co-host:

Ali Yazdani, Princeton University

Please join using the Zoom link below. You'll be able to ask questions during the Q&A by clicking on the hand at the bottom of your screen. The co-host will call on you.