Microwave-Activated Controlled-Z Gate for Fixed-Frequency Fluxonium Qubits

Abstract

The superconducting fluxonium circuit is an artificial atom with a strongly anharmonic spectrum: when biased at a half flux quantum, the lowest qubit transition is an order of magnitude smaller in frequency than those to higher levels. Similar to conventional atomic systems, such a frequency separation between the computational and noncomputational subspaces allows independent optimizations of the qubit coherence and two-qubit interactions. Here we describe a controlled-Z gate for two fluxoniums connected either capacitively or inductively, with qubit transitions fixed near 500 MHz. The gate is activated by a microwave drive at a resonance involving the second excited state. We estimate intrinsic gate fidelities over 99.9% with gate times below 100 ns.

arXiv comment6 pages, 4 figures; published version

References in corpus (35)

• 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
• Simple pulses for elimination of leakage in weakly nonlinear qubits
• Fluxonium: single Cooper pair circuit free of charge offsets
• The Flux Qubit Revisited to Enhance Coherence and Reproducibility
• Superconducting qubit in waveguide cavity with coherence time approaching 0.1ms
• Qubit architecture with high coherence and fast tunable coupling
• Controlling the spontaneous emission of a superconducting transmon qubit
• Procedure for systematically tuning up crosstalk in the cross resonance gate
• A simple all-microwave entangling gate for fixed-frequency superconducting qubits
• A blueprint for demonstrating quantum supremacy with superconducting qubits
• 10-qubit entanglement and parallel logic operations with a superconducting circuit
• Surface participation and dielectric loss in superconducting qubits
• Fidelity of quantum operations
• Implementing the Quantum von Neumann Architecture with Superconducting Circuits
• Introduction to Quantum Electromagnetic Circuits
• A universal gate for fixed-frequency qubits via a tunable bus
• Quantum back-action of variable-strength measurement
• Randomized benchmarking and process tomography for gate errors in a solid-state qubit
• A Rydberg blockade CNOT gate and entanglement in a 2D array of neutral atom qubits
• Fast and Unconditional All-Microwave Reset of a Superconducting Qubit
• Feedback control of a solid-state qubit using high-fidelity projective measurement
• Demonstration of weight-four parity measurements in the surface code architecture
• Experimental demonstration of a resonator-induced phase gate in a multi-qubit circuit QED system
• Microwave-activated conditional-phase gate for superconducting qubits
• Evidence for coherent quantum phase-slips across a Josephson junction array
• Circuit QED with fluxonium qubits: theory of the dispersive regime
• A CNOT gate between multiphoton qubits encoded in two cavities
• Charging effects in the inductively shunted Josephson junction
• Persistent control of a superconducting qubit by stroboscopic measurement feedback
• Protecting a superconducting qubit from energy decay by selection rule engineering
• High-fidelity CZ gate for resonator-based superconducting quantum computers
• Entanglement of distinguishable quantum memories
• Asymptotic Expressions for Charge Matrix Elements of the Fluxonium Circuit

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• The high-coherence fluxonium qubit
• Experimental realization of an intrinsically error-protected superconducting qubit
• Fluxonium: an alternative qubit platform for high-fidelity operations
• Universal fast flux control of a coherent, low-frequency qubit
• Scalable High-Performance Fluxonium Quantum Processor
• Fast logic with slow qubits: microwave-activated controlled-Z gate on low-frequency fluxoniums
• Universal gates for protected superconducting qubits using optimal control
• Long spin coherence times in the ground state and an optically excited state of ${}^{167}$Er${}^{3+}$:Y${}_2$SiO${}_5$ at zero magnetic field
• Fast high-fidelity gates for galvanically-coupled fluxonium qubits using strong flux modulation
• Entangling transmons with low-frequency protected superconducting qubits
• Proposal for entangling gates on fluxonium qubits via a two-photon transition
• Multi-mode architectures for noise-resilient superconducting qubits
• Fast and Robust Geometric Two-Qubit Gates for Superconducting Qubits and beyond
• CNOT gates for fluxonium qubits via selective darkening of transitions
• Speed limits for two-qubit gates with weakly anharmonic qubits
• High coherence fluxonium manufactured with a wafer-scale uniformity process
• Fast Flux Entangling Gate for Fluxonium Circuits
• Classical-Quantum Noise Mitigation for NISQ Hardware
• Microwave-activated gates between a fluxonium and a transmon qubit
• Proposal for transduction between microwave and optical photons using ${}^{167}\mathrm{Er}$-doped yttrium orthosilicate
• Verifying the analogy between transversely coupled spin-1/2 systems and inductively-coupled fluxoniums
• Single-Qubit Gates Beyond the Rotating-Wave Approximation for Strongly Anharmonic Low-Frequency Qubits
• Fast microwave-driven two-qubit gates between fluxonium qubits with a transmon coupler
• Parity-protected superconducting qubit based on topological insulators
• Protected hybrid superconducting qubit in an array of gate-tunable Josephson interferometers