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Updated: Nov 4, 2025
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Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
Published on: August 2, 2019
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Enhanced Coherence in Superconducting Circuits via Band Engineering.
Luca Chirolli1,2, Joel E Moore1,3
1Department of Physics, University of California, Berkeley, California 94720, USA.
Physical Review Letters
|May 21, 2021
Summary
Superconducting circuits with higher-harmonic Josephson elements offer tailored energy spectra. This design enables robust quantum systems, like flux qubits and qutrits, with improved coherence and noise resistance.
Area of Science:
- Quantum Computing
- Condensed Matter Physics
- Superconducting Circuits
Background:
- Superconducting circuits with Josephson junctions exhibit 2e-periodic energy spectra.
- The energy spectrum's dependence on offset charges resembles crystal band structures.
- Existing designs are limited in tailoring the Josephson potential's shape.
Purpose of the Study:
- To explore higher-harmonic Josephson elements for enhanced control over superconducting circuit spectra.
- To design novel quantum systems with improved coherence and noise resilience.
Main Methods:
- Utilized higher-harmonic Josephson elements with a cos(2φ) energy-phase relation.
- Analyzed the resulting energy spectra for flat bands and Dirac points.
- Investigated modified flux qubits and introduced a flux qutrit.
Main Results:
- Achieved tailored Josephson potentials, enabling spectra with flat bands and Dirac points.
- Demonstrated potential for noise-insensitive energy levels through flat spectral gaps.
- Proposed a flux qubit with theoretical immunity to charge noise decoherence.
- Introduced a flux qutrit exhibiting a spin-1 Dirac spectrum robust to charge and flux noise.
Conclusions:
- Higher-harmonic Josephson elements provide significant design freedom for superconducting circuits.
- Engineered flat bands and spectral gaps enhance quantum system coherence.
- Novel qubit and qutrit designs show promise for robust quantum information processing.
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