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Correlating Decoherence in Transmon Qubits: Low Frequency Noise by Single Fluctuators.
Steffen Schlör1, Jürgen Lisenfeld1, Clemens Müller2,3
1Institute of Physics, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany.
Physical Review Letters
|November 26, 2019
Summary
Long-term measurements reveal low-frequency noise in superconducting transmon qubits. This noise originates from microscopic two-level systems at the superconducting film edges, impacting qubit coherence.
Area of Science:
- Quantum Computing
- Condensed Matter Physics
- Superconducting Circuits
Background:
- Superconducting qubits are promising for quantum computation.
- Understanding decoherence mechanisms is crucial for improving qubit performance.
- Josephson qubits are susceptible to intrinsic decoherence.
Purpose of the Study:
- To investigate long-term noise in superconducting transmon qubits.
- To identify the microscopic origins of intrinsic decoherence.
- To correlate noise in coherence times, transition frequency, and relaxation/dephasing rates.
Main Methods:
- Long-term measurements of a superconducting transmon qubit.
- Simultaneous measurement of relaxation rate, dephasing rate, and resonance frequency.
- Correlation analysis between measured parameters.
- Spectral noise analysis.
Main Results:
- Observed low-frequency burst noise in coherence times and qubit transition frequency.
- Correlations between relaxation/dephasing rates and resonance frequency were analyzed.
- Results are consistent with microscopic two-level systems at superconducting film edges.
- Spectral noise analysis confirmed the presence of these two-level systems.
Conclusions:
- Microscopic two-level systems at film edges are a primary source of intrinsic decoherence in these qubits.
- Understanding these noise sources is key to developing more robust quantum hardware.
- The findings provide insights into improving qubit coherence for quantum information processing.
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