Researchers from Karlsruhe Institute of Technology (KIT) in Germany, led by Evgeniya Mutsenik, have made a significant stride in the realm of quantum technology. Their work focuses on developing a basic cell for a quantum microwave router, a crucial component for advancing quantum communication and networking.
The team has successfully created and tested a scalable basic cell for quantum routing. This cell enables the coherent control and exchange of microwave photons between two spatially separated superconducting waveguides. The coupling is facilitated by a single transmon qubit, a type of superconducting quantum bit. The experiments were conducted at an extremely low temperature of 10 milliKelvin, with an average input signal of approximately one photon at around 6 GHz. The qubit was carefully tuned to minimize sensitivity to external magnetic fluctuations.
To characterize the system, the researchers employed a combination of steady-state and time-domain measurements. This allowed them to reconstruct key parameters such as qubit relaxation and dephasing, waveguide-qubit couplings, and cross-waveguide photon transfer efficiency. The observed performance aligns with predictions from a non-Hermitian Hamiltonian formalism, highlighting the impact of flux bias, temperature, and photon number on the system’s behavior. Notably, the cell operates effectively at the single-photon level, and in the high-photon regime, the researchers directly observed photon dressing induced by the qubit.
The results of this study, published in the journal Nature Communications, establish a versatile platform for studying open quantum system phenomena. This breakthrough paves the way for scalable implementations of quantum routing and network nodes, which are essential for the development of quantum communication technologies. The practical applications for the energy sector could include enhanced secure communication networks for power grids and improved sensing technologies for monitoring energy infrastructure.
This research represents a significant step forward in the field of quantum technology, bringing us closer to realizing the full potential of quantum communication and networking. The team’s innovative approach and meticulous experimentation provide a solid foundation for future advancements in this exciting and rapidly evolving field.
This article is based on research available at arXiv.