Fractal Structure of Nanoscale Electron Lines

Erica W. Carlson, Purdue University, DMR 1106187

Fractal structures like trees have many length scales, like one (large) trunk, a few (medium) branches, and many (small) stems. While a tree fills three-dimensional space, other fractals like snowflakes grow in two-dimensional sheets. Carlson’s group discovered that nanoscale electron lines on the surface of cuprate superconductors also form fractals, and developed the theoretical tools to determine whether these fractals grow only on the surface of the material (like a snowflake), or originate deep inside the material (like a tree).

Using these new methods, Carlson and collaborators showed that the nanoscale lines of electrons originate deep inside the material, which means that they may hold the key to superconductivity in these materials.

Purdue physicist Erica Carlson stands in front of an illustration of the fractal clusters present in copper-oxygen based superconducting material. (Purdue University photo/Mark Simons)

http://www.purdue.edu/newsroom/releases/2012/Q3/superconductor-flaws-could-be-key-to-its-abilities.html

http://tinyurl.com/carlson-tedtalk

Are You More Than Your Atoms?

Erica W. Carlson, Purdue University, DMR 1106187

One way to learn about the universe is to break things into their smallest bits, understand those, and put them back together, a paradigm called Reductionism. But in condensed matter physics, we find that many fundamental physical laws cannot be understood by this method.

Using a new paradigm called Emergence, condensed matter physicists seek the universal behavior which can arise from disparate collections of particles. One example is waves, which may arise in water, air, or even crowded baseball stadiums. Emergence is the idea that all of these waves share universal properties.

In this TEDx Talk, Carlson introduces cutting edge ideas of condensed matter physics to the general public.

The Secret Life of Electrons in Superconductors

Erica W. Carlson, Purdue University, DMR 1106187

Students from a local high schoolexplore superconductivity and levitation.

Magnet floating over YBCO,a cuprate superconductor

Carlson explains the quantum mechanics which enables superconducting electrons to carry current without losing energy.

Available online at http://nanohub.org/resources/18549