Print Email Facebook Twitter Feedback control of superconducting quantum circuits Title Feedback control of superconducting quantum circuits Author Ristè, D. Contributor Kouwenhoven, L.P. (promotor) Faculty Applied Sciences Department Quantum Nanoscience Date 2014-10-17 Abstract Superconducting circuits have recently risen to the forefront of the solid-state prototypes for quantum computing. Reaching the stage of robust quantum computing requires closing the loop between measurement and control of quantum bits (qubits). This thesis presents the realization of feedback control of superconducting qubits based on projective measurement, with initial applications. The first application is a reset operation which initializes a qubit in the ground state fast and on demand. In a second experiment, we transform a cavity into a two-qubit parity meter, which is capable of generating entanglement starting from an unentangled superposition state. We then employ feedback to turn the generation of entanglement from probabilistic to deterministic, thus combining two key ingredients - parity measurement and feedback - of quantum error correction. As a third application, we transform a superconducting qubit into a charge-parity detector to investigate the limits of quasiparticle tunneling to qubit coherence. We find room for at least a tenfold increase in qubit coherence times before quasiparticles become the bottleneck. Finally, we present our latest results towards implementing the bit-flip error correction code in a five-qubit processor and discuss the role of feedback control in the future development of superconducting quantum circuits. Subject quantum feedbackquantum measurementsuperconducting qubitsquasiparticlesentanglement To reference this document use: https://doi.org/10.4233/uuid:787bc488-96b2-4e03-abbe-0a9fba2c4d75 ISBN 9789085931966 Part of collection Institutional Repository Document type doctoral thesis Rights (c) 2014 Ristè, D. Files PDF RistePhDThesis_final.pdf 9.27 MB Close viewer /islandora/object/uuid:787bc488-96b2-4e03-abbe-0a9fba2c4d75/datastream/OBJ/view