Realization of high-fidelity CZ and ZZ-free iSWAP gates with a tunable coupler

Abstract

High-fidelity two-qubit gates at scale are a key requirement to realize the full promise of quantum computation and simulation. The advent and use of coupler elements to tunably control two-qubit interactions has improved operational fidelity in many-qubit systems by reducing parasitic coupling and frequency crowding issues. Nonetheless, two-qubit gate errors still limit the capability of near-term quantum applications. The reason, in part, is the existing framework for tunable couplers based on the dispersive approximation does not fully incorporate three-body multi-level dynamics, which is essential for addressing coherent leakage to the coupler and parasitic longitudinal ($ZZ$) interactions during two-qubit gates. Here, we present a systematic approach that goes beyond the dispersive approximation to exploit the engineered level structure of the coupler and optimize its control. Using this approach, we experimentally demonstrate CZ and $ZZ$-free iSWAP gates with two-qubit interaction fidelities of $99.76\pm 0.07$% and $99.87\pm 0.23$%, respectively, which are close to their $T_1$ limits.

34 pages, 39 figures

References in corpus (22)

• Supplementary information for "Quantum supremacy using a programmable superconducting processor"
• Charge insensitive qubit design derived from the Cooper pair box
• QuTiP 2: A Python framework for the dynamics of open quantum systems
• Demonstration of Two-Qubit Algorithms with a Superconducting Quantum Processor
• Hartree-Fock on a superconducting qubit quantum computer
• Quantum Approximate Optimization of Non-Planar Graph Problems on a Planar Superconducting Processor
• Decoherence of flux qubits due to 1/f flux noise
• Repeated Quantum Error Detection in a Surface Code
• Demonstrating a Continuous Set of Two-qubit Gates for Near-term Quantum Algorithms
• Digital quantum simulation of spin models with circuit quantum electrodynamics
• Process verification of two-qubit quantum gates by randomized benchmarking
• High-fidelity, high-scalability two-qubit gate scheme for superconducting qubits
• Controllable coupling of superconducting flux qubits
• Implementation of Conditional-Phase Gates based on tunable ZZ-Interactions
• Machine learning for discriminating quantum measurement trajectories and improving readout
• Suppression of Unwanted $ZZ$ Interactions in a Hybrid Two-Qubit System
• Tunable coupler for realizing a controlled-phase gate with dynamically decoupled regime in a superconducting circuit
• Implementation of the XY interaction family with calibration of a single pulse
• Characterizing and optimizing qubit coherence based on SQUID geometry
• High-contrast ZZ interaction using superconducting qubits with opposite-sign anharmonicity
• Benchmarking Coherent Errors in Controlled-Phase Gates due to Spectator Qubits
• Error analysis in suppression of unwanted qubit interactions for a parametric gate in a tunable superconducting circuit

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• Machine learning of quantum channels on NISQ devices
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• Verifying the analogy between transversely coupled spin-1/2 systems and inductively-coupled fluxoniums
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