Rewritable ‘optical fabrication tagged posts

Artist’s rendition of optically-defined quantum circuits in a topological insulator. Credit: Peter Allen

In contrast to using advanced nanofabrication facilities based on chemical processing of materials, this flexible technique allows for rewritable ‘optical fabrication’ of devices. The electrons in topological insulators have unique quantum properties useful for developing low-power spin-based electronics and quantum computers. However, making even the simplest experimental circuits with these materials has proved difficult because traditional semiconductor engineering techniques tend to destroy their fragile quantum properties. Even a brief exposure to air can reduce their quality.

The researchers report the discovery of an optical effect that allows them to “tune” the energy of electro...