Gyroscopes lead scientists to unusual state of matter in a disorganized structure

You don't have to be perfectly organized to pull off a wave, according to University of Chicago scientists.

Using a set of gyroscopes linked together, physicists explored the behavior of a material whose structure is arranged randomly, instead of an orderly lattice. They found they could set off one-way ripples around the edges, much like spectators in a sports arena—a "topological wave," characteristic of a particularly unusual state of matter.

Published Jan. 15 in Nature Physics, the discovery offers new insight into the physics of collective motion and could one day have implications for electronics, optics or other technologies.

The team, led by Assoc. Prof.WilliamIrvine, used gyroscopes—the top-like toys you played with as a kid—as a model system to explore physics. Because gyroscopes move in three dimensions, if you connect them with springs and spin them with motors, you can observe all kinds of things about the rules that govern how objects move together.

Two years ago, the team observed an odd behavior in their gyroscopes: at certain frequencies, they could set off a wave that traveled around the edges of the material in one direction only. Thiswasstrange, but had some counterparts in other branches of physics. It's a behavior characteristic of a recently discovered state of matter called a topological insulator.