Single-atom switch

From espresso machines to huge mainframe computers, microchips are in almost every electronic device we use. In recent years, researchers have succeeded in making microchips smaller and faster, but the push to get even more miniscule has now hit a wall. That’s why the team at the Center for Single Atom Electronics and Photonics are experimenting on a completely novel microchip – one that functions at the atomic level.

While transistors may seem rather nondescript from the outside, they’re actually powerful electronic components that control, switch or amplify electric currents – and there are billions of these tiny semiconductor “building blocks” on every microchip. In short, transistors are what enable our digital devices to do the actual computing work. But all technological advances notwithstanding – there’s a problem. Transistors consume massive amounts of energy when they process information: data communications and processing account for more than ten percent of overall electricity consumption in industrialised nations.

Researchers in the groups led by Jürg Leuthold and Mathieu Luisier at ETH Zurich and Thomas Schimmel at the Karlsruhe Institute of Technology are seeking to solve this problem by developing a mind-bogglingly efficient single-atom transistor that will significantly reduce energy consumption in computers. Their approach is unique: instead of functioning on the basis of electrons, the microchip of the future will work at the single-atom level or via ions. 

The project, which the Werner Siemens Foundation has been financing since 2017, is well on track. In lab tests, the single-atom switch already uses ten thousand times less energy than today’s silicon semiconductor technology. Part of the success is due to the researchers’ decision to use tin as a novel component for the electrodes. The next step is to transfer the innovative invention into practical application. To do so, the biggest question is how single-atom transistors can be switched simultaneously on a large scale.