The OpenSuperQPlus project aims to build a quantum computer that, in certain tasks, by far outperforms today’s classical supercomputers by moving from

…Classical Parallel Computing…

…to Quantum Computing…

Candidate applications: quantum simulation in chemistry and materials science, optimisation, network analysis, signal processing and machine learning

Quantum advantages:

  • parallel computing without parallel hardware
  • maximum of parallel processes: simultaneously processing the whole input

Quantum challenge:

  • Probabilistic nature of quantum physics in measurement, readout, sampling
  • Sensitivity of quantum computing systems to noise

The Stack

The targeted quantum computing system of up to 1,000 qubits consists of a full hard- and software stack.

The Hardware

Processor based on superconducting integrated circuits plus supporting technology: microwave electronics, control infrastructure and cryogenics.


  • A quantum state showing lossless electrical conduction
  • Common in metals (e.g. Al, Nb)
  • Occuring at low temperature

Josephson Junction

  • Thin barrier between superconductors

The Inner Part

  • Left panel: A Josephson Junction at the heart of the qubit
  • Right panel: A cross-shaped qubit with a Josephson Junction at the upper tip
  • Cross-shape for connectivity

The Outer Part

  • The chip must be connected to input and output
  • Control: double chip package
  • Bridges and pins required


  • Helium dilution cryostat
  • Copper plates to maintain uniform temperature at different stages
  • Input/output: large wiring load
  • The shown insert is in an operated steel can

Control Electronics

  • Qubit control and readout
  • Scalable to large channel number
  • Low latency and high synchronisation accuracy
  • Specialised signal processing


The software stack will be integrated from user access all the way to low-level control and run in a central facility

  • Programming interface for users
  • Operable in a high-performance computing environment
  • Tight integration with classical computers