RSFQubit (RSFQ Control of Josephson Junctions Qubits)

The goal of RSFQubit is to develop a system-on-chip (SoC) solution for a quantum information processor by integrating qubits with superconducting digital electronics, known as Rapid Single Flux Quantum logic. It aims to combine the relatively mature RSFQ technology for superconducting digital electronics with the recently proven capability of Josephson tunnel junction devices to represent qubits, to allow on-chip control of switching and read-out operations in multi-qubit registers and logic gate circuits, with a vision to build an elementary but complete quantum information processing system.

The advantage of such a solution is that an RSFQ classical test bench can operate at the same temperature as qubits, it is compatible with the qubit fabrication process, it is sensitive to signals at a very low energy level and it is fast enough to perform the required digital processing during the short decoherence time.

We are members of the programme and we mainly work to design the qubit quantum shell.
The design of the qubit quantum shell includes the design of all five qubits considered in the proposal together with quantum classical interface to RSFQ circuits.

List of Participants:

1 Chalmers University of Technology (Chalmers) Sweden

2 Physikalisch-TechnischeBundenstalt (PTB) Germany

3 Commissariat al?energie atomique (CEA) France

4 Consiglio Nazionale Delle Ricerche (CNR) Italy

5 Universitaet Karlsruhe (UNIKARL) Germany

6 Universitaet Erlangen-Nuernberg (ERLANGEN) Germany

7 Helsinki University of Technology (HUT) Finland

8 Technical Research Centre of Finland (VTT) Finland

9 Institute for Physical High Technology (Jena) Germany

Kamerlingh Onnes Lab at Leiden University

The initial characterization of our chip requires all the devices to work at the same time and also a very powerful dilution refrigerator.
To achieve this we opened a scientific collaboration with the Kamerlingh Onnes Lab at Leiden University (Prof. Giorgio Frossati). The dutch Lab provides a large variety of dilution refrigerators, ranging from higher to lower refrigerating powers. They permit both fast tests (i.e. with cooling times of a few hours) on small samples and complete testing on the whole system.

Some photos of Leiden' lab: