Lossy Resonators Enable Direct Traveling State Generation

Researchers are directly generating traveling quantum states using microwave-frequency Josephson junctions and nonlinear resonators, sidestepping a key challenge in building quantum networks. Previous architectures relied on tunable couplers to transfer quantum information, but these components can introduce noise and timing issues that reduce fidelity. This new approach eliminates the need for couplers by directly releasing the quantum state into a transmission waveguide. The team describes a system where engineered nonlinear dissipation can shape the emitted waves, forming high-fidelity propagating quantum states in single wave-packet modes. This method, which utilizes constant linear loss to a transmission waveguide, offers a faster release of quantum information and represents…