Microwave-activated high-fidelity three-qubit gate scheme for fixed-frequency superconducting qubits

Abstract

Scalable superconducting quantum processors require balancing critical constraints in coherence, control complexity, and spectral crowding. Fixed-frequency architectures suppress flux noise and simplify control via all-microwave operations but remain limited by residual ZZ crosstalk. Here we propose a microwave-activated three-qubit gate protocol for fixed-frequency transmon qubits in the large-detuning regime ($|\Delta |\gg g$), leveraging the third-order nonlinear interaction to coherently exchange $|001⟩\leftrightarrow |110⟩$ states. By incorporating a phase-compensated optimization protocol, numerical simulations demonstrate a high average gate fidelity exceeding $99.9\%$. Systematic error analysis identifies static long-range ZZ coupling as the dominant error source in multi-qubit systems, which can be suppressed via operations in the large-detuning regime ($\sim 1$ GHz). The protocol maintains process fidelities exceeding $98\%$ under decoherence, while demonstrating intrinsic robustness to fabrication-induced parameter variations and compatibility with existing all-microwave two-qubit gate architectures. This hardware-efficient strategy advances scalable quantum computing systems by improving coherence properties, reducing spectral congestion, and expanding the experimental toolkit for error-resilient quantum operations in the noisy intermediate-scale quantum era.

16 pages, 11 figures

References in corpus (73)

• Quantum Computing in the NISQ era and beyond
• Charge insensitive qubit design derived from the Cooper pair box
• Quantum Simulation
• QuTiP: An open-source Python framework for the dynamics of open quantum systems
• Noisy intermediate-scale quantum (NISQ) algorithms
• Simple pulses for elimination of leakage in weakly nonlinear qubits
• Quantum error correction below the surface code threshold
• Realization of Three-Qubit Quantum Error Correction with Superconducting Circuits
• Efficient Z-Gates for Quantum Computing
• Confining the state of light to a quantum manifold by engineered two-photon loss
• New material platform for superconducting transmon qubits with coherence times exceeding 0.3 milliseconds
• Procedure for systematically tuning up crosstalk in the cross resonance gate
• A simple all-microwave entangling gate for fixed-frequency superconducting qubits
• A tunable coupling scheme for implementing high-fidelity two-qubit gates
• Implementation of a Toffoli Gate with Superconducting Circuits
• Complete universal quantum gate set approaching fault-tolerant thresholds with superconducting qubits
• Transmon qubit with relaxation time exceeding 0.5 milliseconds
• Realization of an Error-Correcting Surface Code with Superconducting Qubits
• Fidelity of quantum operations
• Implementing the Quantum von Neumann Architecture with Superconducting Circuits
• Analytic control methods for high fidelity unitary operations in a weakly nonlinear oscillator
• Realization of high-fidelity CZ and ZZ-free iSWAP gates with a tunable coupler
• Universal fault-tolerant quantum computation with only transversal gates and error correction
• High-fidelity, high-scalability two-qubit gate scheme for superconducting qubits
• Fast adiabatic qubit gates using only ${\sigma }_z$ control
• Beating the break-even point with a discrete-variable-encoded logical qubit
• A fast, low-leakage, high-fidelity two-qubit gate for a programmable superconducting quantum computer
• Fault-tolerant detection of a quantum error
• Demonstration of a High-Fidelity CNOT for Fixed-Frequency Transmons with Engineered ZZ Suppression
• Implementation of Conditional-Phase Gates based on tunable ZZ-Interactions
• High-Fidelity Qutrit Entangling Gates for Superconducting Circuits
• Reducing unitary and spectator errors in cross resonance with optimized rotary echoes
• First-principles analysis of cross-resonance gate operation
• Noisy intermediate-scale quantum computers
• Systematic Improvements in Transmon Qubit Coherence Enabled by Niobium Surface Encapsulation
• High-fidelity controlled-Z gate with maximal intermediate leakage operating at the speed limit in a superconducting quantum processor
• Detecting itinerant microwave photons with engineered non-linear dissipation
• Quantum Algorithm for Spectral Measurement with Lower Gate Count
• High-fidelity three-qubit iToffoli gate for fixed-frequency superconducting qubits
• Scalable High-Performance Fluxonium Quantum Processor
• Single qubit gates in frequency-crowded transmon systems
• Quantum crosstalk cancellation for fast entangling gates and improved multi-qubit performance
• Hardware-Efficient Microwave-Activated Tunable Coupling Between Superconducting Qubits
• Calibration of the cross-resonance two-qubit gate between directly-coupled transmons
• Five Two-Qubit Gates Are Necessary for Implementing Toffoli Gate
• Long-distance transmon coupler with CZ gate fidelity above $99.8\%$
• Programmable Heisenberg interactions between Floquet qubits
• Fast parametric two-qubit gates with suppressed residual interaction using a parity-violated superconducting qubit
• Demonstration of an All-Microwave Controlled-Phase Gate between Far Detuned Qubits
• Fast multi-qubit gates through simultaneous two-qubit gates
• Suppression of static ZZ interaction in an all-transmon quantum processor
• Extensive characterization of a family of efficient three-qubit gates at the coherence limit
• Coupler-Assisted Controlled-Phase Gate with Enhanced Adiabaticity
• Two-photon driven Kerr resonator for quantum annealing with three-dimensional circuit QED
• Realization of High-Fidelity CZ Gate based on a Double-Transmon Coupler
• Double-Transmon Coupler: Fast Two-Qubit Gate with No Residual Coupling for Highly Detuned Superconducting Qubits
• Mitigation of interfacial dielectric loss in aluminum-on-silicon superconducting qubits
• Fast microwave-driven three-qubit gates for cavity-coupled superconducting qubits
• Empowering high-dimensional quantum computing by traversing the dual bosonic ladder
• Scalable and robust quantum computing on qubit arrays with fixed coupling
• Native two-qubit gates in fixed-coupling, fixed-frequency transmons beyond cross-resonance interaction
• High fidelity quantum gates via analytically solvable pulses
• Controlled-Controlled-Phase Gates for Superconducting Qubits Mediated by a Shared Tunable Coupler
• Single Shot i-Toffoli Gate in Dispersively Coupled Superconducting Qubits
• Cross cross resonance gate
• Simultaneously exciting two atoms with photon-mediated Raman interaction
• All-microwave manipulation of superconducting qubits with a fixed-frequency transmon coupler
• ScQ cloud quantum computation for generating Greenberger-Horne-Zeilinger states of up to 10 qubits
• High-precision pulse calibration of tunable couplers for high-fidelity two-qubit gates in superconducting quantum processors
• Direct Implementation of High-Fidelity Three-Qubit Gates for Superconducting Processor with Tunable Couplers
• Tantalum airbridges for scalable superconducting quantum processors
• Resonant Schrödinger Cat States in Circuit Quantum Electrodynamics
• Fast ZZ-Free Entangling Gates for Superconducting Qubits Assisted by a Driven Resonator