QDev Seminar: Angela Kou – University of Copenhagen

QDev Seminar: Angela Kou

Department of Applied Physics, Yale University

Fluxonium Qubit in a Waveguide

Superconducting qubits are created by connecting Josephson junctions, which are non-linear, non-dissipative elements, to simple electrical circuits. In particular, the qubit is a Josephson junction connected to a large inductance. This qubit has demonstrated large anharmonicity, long coherence times, and tunability with respect to applied external ux. In this talk, I will present a new architecture for measuring the uxonium qubit and its readout resonator. We embed the qubit-resonator system in a waveguide, which enables coupling of the device to a low-loss traveling wave environment. We demonstrate that this architecture allows for multiplexed readout of multiple uxonium qubits. Using cascaded quantum-limited ampliers, we are able to monitor the quantum jumps of two qubits simultaneously. I will also briey mention work on coupling multiple uxonium qubits in a 1-dimensional array and the prospects for quantum simulation using this array.