From size to stability, from integration to networking: MILLENION will tackle the pressing challenges that quantum computers face on their path from the laboratory to industry scale. As successor to the EU flagship project AQTION, the MILLENION collaboration combines academic and industrial leaders across Europe to deliver a modular and scalable quantum computing suite with high performance cluster integration and a fault-tolerant register of 1000 qubits.

Besides aiding in the design of scalable ion-trap architectures [1], our group focuses on fault-tolerant approaches to universal quantum computation with logical qubits. In this regard, we developed a protocol to fault-tolerantly switch between two codes in which different types of gates can be accomplished transversally [2], thus together yielding a universal gate set in which errors never spread uncontrollably. In collaboration with UIBK, we subsequently demonstrated an experimental realisation [3] with an ion-trap quantum computer.