Bidirectional Multi-Photon Communication between Remote Superconducting Resonators

The field of quantum communication involves sending quantum states from one location to another. This has potential applications in building secure communication channels through quantum cryptography as well as in sharing resources between quantum computers that are part of a quantum network. Quantum communication protocols based on multi-photon states can support greater transmitted information density than those relying on single photon states. Bidirectional communication in a waveguide would further increase channel efficiency. At microwave frequencies, recent experiments have encoded multi-photon states in a superconducting resonator, deterministically transmitted them as wave packets into a waveguide, and captured them at remote nodes. However, while bidirectional communication has been demonstrated with single photon states, remote communication using multi-photon wave packets have been limited to a single propagation direction. In this thesis we present an experiment demonstrating bidirectional multi-photon transfers between two remote tunable resonators in a superconducting system, enabling single-pass on-demand transfers of photon superposition states. A second project is also presented that discusses the design and fabrication of a Josephson Parametric Amplifier with wide bandwidth, high gain, and low added noise. This amplifier incorporates innovations from previously demonstrated designs into a single device to improve performance while still being simple enough to fabricate in an academic cleanroom.