Our approach to scalable quantum computing

Scaling quantum computers from small devices of academic relevance to large, end-user-centric computers of industrial relevance requires overcoming countless challenges. Innovative ideas are thus key to progress towards MILLENION’s ultimate goal. The scaling strategy pursued by MILLENION is threefold: Scaling up, scaling down, and scaling out.

MILLENION's holistic system design approach from processor and real-time-control (RTC) to quantum subroutines such as error correction (QEC) and characterisation, verification and validation (QCVV). Credit: Ch. Marciniak
MILLENION's holistic system design approach from processor and real-time-control (RTC) to quantum subroutines such as error correction (QEC) and characterisation, verification and validation (QCVV). Credit: Ch. Marciniak

MILLENION will scale up the number of qubits with the goal of controlling 1000 qubits in a fault-tolerant manner – both by improving the intrinsic fidelities of quantum operations below the necessary thresholds, and through the use of fault-tolerant quantum circuit design principles.

MILLENION will scale down the quantum processor footprint by adopting fabrication processes that are reproducible and modular, including the direct integration of fibre optics and electronics using techniques adapted from the semiconductor industry.

MILLENION will scale out by ion-transport operations, and by preparing interfaces to connect different processors, both within a vacuum chamber (multi-core processors) and between individual devices (following design principles of HPC clusters).

Integrated optics for light-matter interactions on chip
Integrated optics for light-matter interactions on chip. Credit: G. Ouwekerk
Ion transport allows for reconfigurable and dynamic registers through transport primitives such as merging, splitting, swapping, or shuttling.
Ion transport allows for reconfigurable and dynamic registers through transport primitives such as merging, splitting, swapping, or shuttling.

The diverse expertise gathered in MILLENION will be able to tackle the many challenges across the quantum computing stack and actively shape the development of the quantum ecosystem within Europe, exploiting the synergies that only be achieved by close connection and a common goal.