High-coherence fluxonium qubits manufactured with a wafer-scale-uniformity process
Fluxonium qubits are recognized for their high coherence times and high operation fidelities. These are attributed to their unique design incorporating a superinductor, which is typically implemented using an array of over 100 Josephson junctions; however, this complexity poses significant fabrication challenges, particularly in achieving high yield and junction uniformity with traditional methods. Here, we introduce an overlap process for Josephson-junction fabrication that achieves nearly 100% yield and maintains uniformity across a 2-inch (50.8-mm) wafer with less than 5% variation for the phase-slip junction and less than 2% for the entire junction array. We use a compact junction array design that achieves state-of-the-art dielectric loss tangents and flux noise levels, as confirmed by multiple devices. This enables fluxonium qubits to reach energy relaxation times exceeding 1 ms at the flux-frustration point. This work paves the way for scalable, high-coherence fluxonium processors using processes compatible with complementary metal-oxide semiconductor manufacturing, marking a significant step toward practical quantum computing.
Authors
- Xun Gao (ORCID: https://orcid.org/0000-0002-2989-0292)
- Tao Zhou (ORCID: https://orcid.org/0009-0000-6289-3834)
- Honghong Ji
- Hui‐Hai Zhao (ORCID: https://orcid.org/0000-0001-7075-8325)
- Hantao Sun (ORCID: https://orcid.org/0009-0009-7549-5312)
- Zhijun Song (ORCID: https://orcid.org/0000-0002-3844-186X)
- Gengyan Zhang (ORCID: https://orcid.org/0009-0000-4228-6527)
- Rui-Zi Hu (ORCID: https://orcid.org/0000-0001-5346-7665)
- Yang Bai (ORCID: https://orcid.org/0000-0002-2325-9467)
- Hongcheng Wang (ORCID: https://orcid.org/0000-0001-6842-4326)
- Tenghui Wang (ORCID: https://orcid.org/0000-0003-1605-4153)
- Kannan Lu (ORCID: https://orcid.org/0000-0003-4400-1964)
- Hao Deng (ORCID: https://orcid.org/0000-0002-1656-229X)
- Xizheng Ma (ORCID: https://orcid.org/0000-0001-7949-9809)
- Chengchun Tang (ORCID: https://orcid.org/0000-0003-3767-3551)
- Lijuan Hu (ORCID: https://orcid.org/0000-0003-1869-0372)
- Ziang Wang (ORCID: https://orcid.org/0009-0002-4931-7781)
- Feng Bao (ORCID: https://orcid.org/0000-0002-0573-9002)
- Feng Wu (ORCID: https://orcid.org/0000-0003-1652-9243)
- Huijuan Zhan
- Fei Wang (ORCID: https://orcid.org/0000-0002-8626-997X)
- Hongxin Xu (ORCID: https://orcid.org/0009-0001-6031-9983)
- Lu Ma
- Shasha Zhu
- Mengyu Zhu
- Liyong Mao
- Ran Gao (ORCID: https://orcid.org/0000-0002-8505-6972)
- Tian Xia (ORCID: https://orcid.org/0000-0001-9136-6638)
- Xing Zhu (ORCID: https://orcid.org/0000-0003-3665-8667)
- Xu Chang (ORCID: https://orcid.org/0000-0002-1127-7668)
- Guicheng Gong
- Yaoyun Shi (ORCID: https://orcid.org/0000-0001-5523-6166)
- Qingbin Zhu
- Ze Zhan
- Chunqing Deng
Institutions
- Hefei University of Technology (CN)
- Peking University (CN)
- Quantum (Australia) (AU)
- IAP Research (United States) (US)
- Zhejiang Lab (CN)
- China Telecom (China) (CN)
- Jordan Valley Semiconductors (China) (CN)
- China Telecom (CN)
- Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area (CN)
- Zhejiang University (CN)
- United Microelectronics (United States) (US)
Publication Details
- Journal
- Physical Review Applied
- Published
- 2025-04-29
- DOI
- https://doi.org/10.1103/physrevapplied.23.044064
- Citations
- 12
- Primary Topic
- Quantum Information and Cryptography
- Type
- article
- Field-Weighted Citation Impact
- 29.77