Collateral Coupling between Superconducting Resonators: Fast High-Fidelity Generation of Qudit-Qudit Entanglement
Pedro Rosário, Alan C. Santos, Celso J. Villas-Bôas, Romain Bachelard · Physical Review Applied · 2023
Superconducting circuits are highly controllable platforms to manipulate quantum states, which make them particularly promising for quantum information processing. We show here how the existence of a distance-independent interaction between microwave resonators coupled capacitively through a qubit offers an alternative control parameter toward this goal. This interaction is able to induce an idling point between resonant resonators, and its state-dependent nature allows one to control the flow of information between the resonators. The advantage of this scheme over the previous one is demonstrated through the generation of high-fidelity NOON states between the resonators, with a lower number of operations than previous schemes. Beyond superconducting circuits, our proposal could also apply to atomic lattices with clock transitions in optical cavities, for example.