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Exploration of Protected Qubit Architectures and Two-Qubit Gate Design
Exploration of Protected Qubit Architectures and Two-Qubit Gate Design
Detailed Information
- 자료유형
- 학위논문 서양
- 최종처리일시
- 20260311091508.5
- ISBN
- 9798315702108
- DDC
- 530
- 저자명
- Liu, Zhenxing
- 서명/저자
- Exploration of Protected Qubit Architectures and Two-Qubit Gate Design / Zhenxing Liu
- 발행사항
- [Sl] : University of Colorado at Boulder, 2025
- 형태사항
- 1 electronic resource (162 pages)
- 주기사항
- Source: Dissertations Abstracts International, Volume: 86-11, Section: B.
- 주기사항
- Advisors: Combes, Joshua Committee members: Gyenis, Andras; Teufel, John; Aumentado, Jose; Cao, Gang.
- 학위논문주기
- - Ph.D. : University of Colorado at Boulder, 2025.
- 초록/해제
- 요약This dissertation explores three types of protected superconducting qubits: the rhombus qubit, the 0-π qubit, and the gyrator qubit. For the rhombus qubit, we analyze both symmetric and asymmetric circuit variants, quantizing the system and comparing their energy spectra. We find that the symmetric rhombus exhibits exponential protection against both depolarization and charge noise-induced dephasing. Importantly, we show that introducing asymmetry yields a first-order flux noise sweet spot, which can significantly extend qubit coherence and improve gate depth.For the soft 0-π qubit, we study single- and two-qubit gates using microwave drives. We demonstrate that driving nθ achieves higher-fidelity single qubit X gate than driving nφ, with simulated fidelities ∼ 99.9% and gate time ∼ 30 ns for T1 = Tφ = 30µs. We also develop two kinds of two-qubit gates, CZ and CNOT gates. These gates are realized using both direct and Raman-type transitions, with fidelities ∼ 99.9% and gate times around 160 ns for T1 = Tφ = 30µs.We also propose a method to generate GKP states using parametrically induced gyration between coupled oscillators. We describe a circuit implementation using a modulated inductor and derive the corresponding quantum Hamiltonian. Importantly I show that having an imperfect gyration ratio degrades the code space of gyrator qubit.Finally I develop a graph-theoretic approach to enumerate superconducting circuits and identify candidates with favorable coherence properties. Applying this framework, we compare transmon, fluxonium, and rhombus qubits in terms of relaxation time, dephasing, and expected gate count, finding that the asymmetric rhombus offers competitive, and potentially superior, performance.
- 언어주기
- English
- 일반주제명
- Quantum physics
- 일반주제명
- Computer engineering
- 일반주제명
- Computer science
- 키워드
- Protected qubits
- 키워드
- Energy spectra
- 키워드
- Fluxonium
- 기타저자
- University of Colorado at Boulder Materials Science and Engineering
- 기본자료저록
- Dissertations Abstracts International. 86-11B.
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
008260311s2025 us eng d■001000017357012
■00520260311091508.5
■006m o d
■007cr|nu||||||||
■020 ▼a9798315702108
■040 ▼aMiAaPQD▼beng▼cMiAaPQD▼erda
■082 ▼a530
■1001 ▼aLiu, Zhenxing▼eauthor.
■24510▼aExploration of Protected Qubit Architectures and Two-Qubit Gate Design ▼cZhenxing Liu
■260 ▼a[Sl]▼bUniversity of Colorado at Boulder▼c2025
■264 1▼aAnn Arbor▼bProQuest Dissertations & Theses▼c2025
■300 ▼a1 electronic resource (162 pages)
■336 ▼atext▼btxt▼2rdacontent
■337 ▼acomputer▼bc▼2rdamedia
■338 ▼aonline resource▼bcr▼2rdacarrier
■500 ▼aSource: Dissertations Abstracts International, Volume: 86-11, Section: B.
■500 ▼aAdvisors: Combes, Joshua Committee members: Gyenis, Andras; Teufel, John; Aumentado, Jose; Cao, Gang.
■5021 ▼bPh.D.▼cUniversity of Colorado at Boulder▼d2025.
■520 ▼aThis dissertation explores three types of protected superconducting qubits: the rhombus qubit, the 0-π qubit, and the gyrator qubit. For the rhombus qubit, we analyze both symmetric and asymmetric circuit variants, quantizing the system and comparing their energy spectra. We find that the symmetric rhombus exhibits exponential protection against both depolarization and charge noise-induced dephasing. Importantly, we show that introducing asymmetry yields a first-order flux noise sweet spot, which can significantly extend qubit coherence and improve gate depth.For the soft 0-π qubit, we study single- and two-qubit gates using microwave drives. We demonstrate that driving nθ achieves higher-fidelity single qubit X gate than driving nφ, with simulated fidelities ∼ 99.9% and gate time ∼ 30 ns for T1 = Tφ = 30µs. We also develop two kinds of two-qubit gates, CZ and CNOT gates. These gates are realized using both direct and Raman-type transitions, with fidelities ∼ 99.9% and gate times around 160 ns for T1 = Tφ = 30µs.We also propose a method to generate GKP states using parametrically induced gyration between coupled oscillators. We describe a circuit implementation using a modulated inductor and derive the corresponding quantum Hamiltonian. Importantly I show that having an imperfect gyration ratio degrades the code space of gyrator qubit.Finally I develop a graph-theoretic approach to enumerate superconducting circuits and identify candidates with favorable coherence properties. Applying this framework, we compare transmon, fluxonium, and rhombus qubits in terms of relaxation time, dephasing, and expected gate count, finding that the asymmetric rhombus offers competitive, and potentially superior, performance.
■546 ▼aEnglish
■590 ▼aSchool code: 0051
■650 4▼aQuantum physics
■650 4▼aComputer engineering
■650 4▼aComputer science
■653 ▼aProtected qubits
■653 ▼aQuantum computing
■653 ▼aSuperconducting qubits
■653 ▼aEnergy spectra
■653 ▼aFluxonium
■7102 ▼aUniversity of Colorado at Boulder▼bMaterials Science and Engineering.▼edegree granting institution.
■7201 ▼aCombes, Joshua▼edegree supervisor.
■7730 ▼tDissertations Abstracts International▼g86-11B.
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T17357012▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.
