Alexandria Digital Research Library

Fault-tolerant superconducting qubits

Author:
Kelly, Julian S.
Degree Grantor:
University of California, Santa Barbara. Physics
Degree Supervisor:
John Martinis
Place of Publication:
[Santa Barbara, Calif.]
Publisher:
University of California, Santa Barbara
Creation Date:
2015
Issued Date:
2015
Topics:
Physics, Quantum and Computer Science
Keywords:
Qubits
Digital
Quantum computing
Surface code
Superconducting
Quantum error correction
Genres:
Dissertations, Academic and Online resources
Dissertation:
Ph.D.--University of California, Santa Barbara, 2015
Description:

For quantum computing to become viable, the inherently fallible nature of qubits must be overcome with quantum error correction (QEC). QEC requires coherent qubits, in a configuration compatible with a given QEC scheme, and quantum logic operations with sufficiently low error. In this thesis, we perform a series of targeted experiments to achieve these goals on a path toward realizing the surface code QEC scheme. We first develop the Xmon variant of the transmon qubit, a highly coherent, planar, and frequency tunable superconducting qubit. With coherence demonstrated, we build an array of five Xmon qubits in a configuration compatible with the surface code, and demonstrate quantum logic operations with sufficiently low error to employ the surface code. These logic gates are characterized with randomized benchmarking, a protocol for determining gate error. We find applications of randomized benchmarking beyond the intended use in gate optimization and decoherence characterization, in addition to exploring the fundamental assumptions of randomized benchmarking. Lastly, we build a nine qubit Xmon transmon array and demonstrate correction of environmental bit-flip errors in a precursor to the surface code.

Physical Description:
1 online resource (269 pages)
Format:
Text
Collection(s):
UCSB electronic theses and dissertations
ARK:
ark:/48907/f3b56gwb
ISBN:
9781321696349
Catalog System Number:
990045119450203776
Rights:
Inc.icon only.dark In Copyright
Copyright Holder:
Julian Kelly
File Description
Access: Public access
Kelly_ucsb_0035D_12517.pdf pdf (Portable Document Format)