Research News

Nature doesn’t have the best memory. If you fill a box with air and divide it in half with a barrier, it’s easy to tell molecules on the left from molecules on the right. But after removing the barrier and waiting a short while, the molecules get mixed together, and it becomes impossible to tell where a given molecule started. The air-in-a-box system loses any memory of its initial conditions.

Scientists studying an exotic material have found a potential application for its unusual properties, a discovery that could improve devices found in most digital electronics.

Under the right conditions the material, a compound called samarium hexaboride, is a topological insulator—something that conducts electricity on its surface but not through its interior. The first examples of topological insulators were only recently created in the lab, and their discovery has sparked a great deal of theoretical and experimental interest.

The behavior of a few rubidium atoms in a cloud of 40,000 hardly seems important. But a handful of the tiny particles with the wrong energy may cause a cascade of effects that could impact future quantum computers.

Some proposals for quantum devices use Rydberg atoms—atoms with highly excited electrons that roam far from the nucleus—because they interact strongly with each other and offer easy handles for controlling their individual and collective behavior. Rubidium is one of the most popular elements for experimenting with Rydberg physics.