Above 99.9% Fidelity Single-Qubit Gates, Two-Qubit Gates, and Readout in a Single Superconducting Quantum Device
read the original abstract
Achieving high-fidelity single-qubit gates, two-qubit gates, and qubit readout is critical for building scalable, error-corrected quantum computers. However, device parameters that enhance one operation often degrade the others, making simultaneous optimization challenging. Here, we demonstrate that careful tuning of qubit-coupler coupling strengths in a superconducting circuit with two transmon qubits coupled via a tunable coupler enables high-fidelity single- and two-qubit gates, without compromising readout performance. As a result, we achieve a 40h-averaged CZ gate fidelity of 99.93%, simultaneous single-qubit gate fidelities of 99.98%, and readout fidelities over 99.94% in a single device. These results are enabled by optimized coupling parameters, an efficient CZ gate calibration experiment based on our new Phased-Averaged Leakage Error Amplification (PALEA) protocol, and a readout configuration compatible with high coherence qubits. Our results demonstrate a viable path toward scaling up superconducting quantum processors while maintaining consistently high fidelities across all core operations.
This paper has not been read by Pith yet.
Forward citations
Cited by 9 Pith papers
-
Adversarial Effects on Expressibility and Trainability in Distributed Variational Quantum Algorithms
Adversaries perturbing shared entanglement in distributed VQAs can manipulate a new Kraus expressibility metric to keep gradients large but steer training to incorrect solutions.
-
Parametrically Driven iSWAP Gate Using a Capacitively Shunted Double-Transmon Coupler at the Zero-Flux Sweet Spot
A capacitively shunted double-transmon coupler enables a 99.92% fidelity parametrically driven iSWAP gate at zero flux between detuned transmons with minimal residual ZZ interaction.
-
Systematic frequency-collision analysis of the cross-resonance gate outside the straddling regime
Far-detuned cross-resonance designs cut frequency collisions in transmon processors, achieving 10% collision-free yield for 1024 qubits with qubit-frequency spread reduced to 6.8 MHz.
-
Demonstrating Record Fidelity for the Quantum Fourier Transform
Parity Architecture delivers record ~0.01 fidelity for 50-qubit QFT on IBM hardware with super-exponential scaling improvement.
-
Improving Feasibility in Quantum Approximate Optimization Algorithm for Vehicle Routing via Constraint-Aware Initialization and Hybrid XY-X Mixing
Constraint-aware initialization and hybrid XY-X mixer in QAOA for VRP yield lower average energies and higher feasible-solution ratios than standard QAOA across ideal, finite-shot, and noisy simulations.
-
Unlocking a fast adiabatic CZ gate and exact residual $ZZ$ cancellation between fixed-frequency transmons using a floating tunable coupler
A floating tunable coupler allows 24 ns adiabatic CZ gates above 99.9% fidelity with exact ZZ=0 at idle for fixed-frequency transmons.
-
Quantum Simulation of Ligand-like Molecules through Sample-based Quantum Diagonalization in Density Matrix Embedding Framework
DMET combined with SQD on IBM Eagle hardware achieves chemical accuracy for ground-state energies of low-symmetry ligand-like molecules.
-
Optimal Control of thermally noisy quantum gates in a multilevel system
Optimal control theory designs high-fidelity quantum gates in multilevel systems that incorporate thermal relaxation and enable targeted cooling or heating during operation.
-
Characterizing charge-parity detection based on an offset-charge-tunable transmon qubit via randomized benchmarking
Offset-charge-tunable transmon qubit achieves 99.37% fidelity in charge-parity mapping and over 93.4% in continuous monitoring at 4 μs intervals via randomized benchmarking.
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.