Research News

Quantum computers promise speedy solutions to some difficult problems, but building large-scale, general-purpose quantum devices is a problem fraught with technical challenges.

To date, many research groups have created small but functional quantum computers. By combining a handful of atoms, electrons or superconducting junctions, researchers now regularly demonstrate quantum effects and run simple quantum algorithms—small programs dedicated to solving particular problems.

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.