Research Approach

Overview

The full potential of quantum devices can only be leveraged if they can be connected. In the Superspin project, a superconducting qubit operating at microwave frequency is linked to a diamond‑based quantum memory that stores information in spin states that can be addressed by visible photons. The collaboration is funded by the European Innovation Council’s Pathfinder programme and involves partners from Karlsruhe Institut for Technology, Aalto University, Palacký University Olomouc, and the start‑up QphoX.  

How It Works 

To bridge the frequency mismatch, we use quantum transducers that first convert fragile microwave qubit states into telecom photons, which can propagate with minimal loss through long‑distance optical fibers. The photons get then frequency converted to visible light to interact with the quantum memory. Thereby, the entangled state is stored and can be retrieved on demand, creating a reliable quantum link between the two disparate systems.  

Transmission in Optical Fibers 

The transduced photons act as “flying qubits,” traveling nearly losslessly in optical fibers. By exploiting quantum entanglement, a change in one particle instantly influences its partner, regardless of the physical separation, which ensures faithful transmission of quantum information across the network.