At Karlsruhe Institute of Technology (KIT), physicist Professor Thomas Schimmel and his team have developed a single-atom transistor, the smallest transistor in existence. This quantum electronics component switches electrical current by controlled repositioning of a single atom, now also in the solid state in a gel electrolyte. The single-atom transistor works at room temperature and consumes very little energy, which opens up entirely new perspectives for information technology. The transistor is presented in Advanced Materials.