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The Flux Qubit Revisited to Enhance Coherence and Reproducibility
- Source :
- Nature Communications, Vol 7, Iss 1, Pp 1-9 (2016), Nature, Nature Communications
- Publication Year :
- 2015
-
Abstract
- The scalable application of quantum information science will stand on reproducible and controllable high-coherence quantum bits (qubits). Here, we revisit the design and fabrication of the superconducting flux qubit, achieving a planar device with broad-frequency tunability, strong anharmonicity, high reproducibility and relaxation times in excess of 40 μs at its flux-insensitive point. Qubit relaxation times T1 across 22 qubits are consistently matched with a single model involving resonator loss, ohmic charge noise and 1/f-flux noise, a noise source previously considered primarily in the context of dephasing. We furthermore demonstrate that qubit dephasing at the flux-insensitive point is dominated by residual thermal-photons in the readout resonator. The resulting photon shot noise is mitigated using a dynamical decoupling protocol, resulting in T2≈85 μs, approximately the 2T1 limit. In addition to realizing an improved flux qubit, our results uniquely identify photon shot noise as limiting T2 in contemporary qubits based on transverse qubit–resonator interaction.<br />Scalable quantum information processing requires controllable high-coherence qubits. Here, the authors present superconducting flux qubits with broad frequency tunability, strong anharmonicity and high reproducibility, identifying photon shot noise as the main source of dephasing for further improvements.
- Subjects :
- Flux qubit
Charge qubit
Science
Dephasing
FOS: Physical sciences
General Physics and Astronomy
02 engineering and technology
01 natural sciences
Article
General Biochemistry, Genetics and Molecular Biology
Phase qubit
Computer Science::Emerging Technologies
Quantum mechanics
0103 physical sciences
010306 general physics
Quantum information science
Physics
Quantum Physics
Multidisciplinary
Shot noise
General Chemistry
021001 nanoscience & nanotechnology
Qubit
Quantum Physics (quant-ph)
0210 nano-technology
Superconducting quantum computing
Subjects
Details
- Language :
- English
- Database :
- OpenAIRE
- Journal :
- Nature Communications, Vol 7, Iss 1, Pp 1-9 (2016), Nature, Nature Communications
- Accession number :
- edsair.doi.dedup.....60d66a619d2189ca196ec702ed78d5e3