The quantum internet requires many components. Two important elements are the quantum processor that usually works in the microwave regime, and the transferring of the quantum state over the long distances and detecting it that usually takes place in the optical regime. In this seminar, I will talk about some recent developments in these two areas using superconducting nanostructures.

In the first half of this seminar, I will talk about Superconducting Nanowire Single Photon Detectors (SNSPD). I will show that by engineering properties of vortices in thin superconducting nanowires, we can significantly improve the quantum efficiency, and drastically decrease the dark count rate in SNSPDs. The second half will be devoted to Quantum Phase Slips (QPS) in 1D-superconducting nanowires. QPS junctions are conjectured to be dual to Josephson junctions. QPS qubits are assumed to have a better performance in terms of the decoherence and ease of fabrication compared to Josephson junction based qubits. I will talk about the behavior of QPS junctions in microwave field. It will be shown that the quantum tunneling can be dramatically increased in the presence of microwave field. Finally, we will propose a new class of high-frequency detectors based on QPS in 1D-superconducting nanowires.