--- _id: '12366' abstract: - lang: eng text: "Recent substantial advances in the feld of superconducting circuits have shown its\r\npotential as a leading platform for future quantum computing. In contrast to classical\r\ncomputers based on bits that are represented by a single binary value, 0 or 1, quantum\r\nbits (or qubits) can be in a superposition of both. Thus, quantum computers can store\r\nand handle more information at the same time and a quantum advantage has already\r\nbeen demonstrated for two types of computational tasks. Rapid progress in academic\r\nand industry labs accelerates the development of superconducting processors which may\r\nsoon fnd applications in complex computations, chemical simulations, cryptography, and\r\noptimization. Now that these machines are scaled up to tackle such problems the questions\r\nof qubit interconnects and networks becomes very relevant. How to route signals on-chip\r\nbetween diferent processor components? What is the most efcient way to entangle\r\nqubits? And how to then send and process entangled signals between distant cryostats\r\nhosting superconducting processors?\r\nIn this thesis, we are looking for solutions to these problems by studying the collective\r\nbehavior of superconducting qubit ensembles. We frst demonstrate on-demand tunable\r\ndirectional scattering of microwave photons from a pair of qubits in a waveguide. Such a\r\ndevice can route microwave photons on-chip with a high diode efciency. Then we focus\r\non studying ultra-strong coupling regimes between light (microwave photons) and matter\r\n(superconducting qubits), a regime that could be promising for extremely fast multi-qubit\r\nentanglement generation. Finally, we show coherent pulse storage and periodic revivals\r\nin a fve qubit ensemble strongly coupled to a resonator. Such a reconfgurable storage\r\ndevice could be used as part of a quantum repeater that is needed for longer-distance\r\nquantum communication.\r\nThe achieved high degree of control over multi-qubit ensembles highlights not only the\r\nbeautiful physics of circuit quantum electrodynamics, it also represents the frst step\r\ntoward new quantum simulation and communication methods, and certain techniques\r\nmay also fnd applications in future superconducting quantum computing hardware.\r\n" acknowledged_ssus: - _id: NanoFab - _id: M-Shop - _id: EM-Fac alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Elena full_name: Redchenko, Elena id: 2C21D6E8-F248-11E8-B48F-1D18A9856A87 last_name: Redchenko citation: ama: Redchenko E. Controllable states of superconducting Qubit ensembles. 2022. doi:10.15479/at:ista:12132 apa: Redchenko, E. (2022). Controllable states of superconducting Qubit ensembles. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:12132 chicago: Redchenko, Elena. “Controllable States of Superconducting Qubit Ensembles.” Institute of Science and Technology Austria, 2022. https://doi.org/10.15479/at:ista:12132. ieee: E. Redchenko, “Controllable states of superconducting Qubit ensembles,” Institute of Science and Technology Austria, 2022. ista: Redchenko E. 2022. Controllable states of superconducting Qubit ensembles. Institute of Science and Technology Austria. mla: Redchenko, Elena. Controllable States of Superconducting Qubit Ensembles. Institute of Science and Technology Austria, 2022, doi:10.15479/at:ista:12132. short: E. Redchenko, Controllable States of Superconducting Qubit Ensembles, Institute of Science and Technology Austria, 2022. date_created: 2023-01-25T09:17:02Z date_published: 2022-09-26T00:00:00Z date_updated: 2023-05-26T09:29:07Z day: '26' ddc: - '530' degree_awarded: PhD department: - _id: GradSch - _id: JoFi doi: 10.15479/at:ista:12132 ec_funded: 1 file: - access_level: open_access checksum: 39eabb1e006b41335f17f3b29af09648 content_type: application/pdf creator: cchlebak date_created: 2023-01-25T09:41:49Z date_updated: 2023-01-26T23:30:44Z embargo: 2022-12-28 file_id: '12367' file_name: Final_Thesis_ES_Redchenko.pdf file_size: 56076868 relation: main_file file_date_updated: 2023-01-26T23:30:44Z has_accepted_license: '1' language: - iso: eng month: '09' oa: 1 oa_version: Published Version page: '168' project: - _id: 2564DBCA-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '665385' name: International IST Doctoral Program - _id: 26336814-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '758053' name: A Fiber Optic Transceiver for Superconducting Qubits - _id: 237CBA6C-32DE-11EA-91FC-C7463DDC885E call_identifier: H2020 grant_number: '862644' name: Quantum readout techniques and technologies publication_identifier: isbn: - 978-3-99078-024-4 issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria status: public supervisor: - first_name: Johannes M full_name: Fink, Johannes M id: 4B591CBA-F248-11E8-B48F-1D18A9856A87 last_name: Fink orcid: 0000-0001-8112-028X title: Controllable states of superconducting Qubit ensembles type: dissertation user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9 year: '2022' ...