Balanced cross-Kerr coupling for superconducting qubit readout
arXiv:2501.09010 · doi:10.1103/r4v5-wyyt
Abstract
Dispersive readout, the standard method for measuring superconducting qubits, is limited by multiphoton qubit-resonator processes arising even at moderate drive powers. These processes degrade performance, causing dispersive readout to lag behind single- and two-qubit gates in both speed and fidelity. In this work, we propose a novel readout method, termed "junction readout". Junction readout leverages the nonperturbative cross-Kerr interaction resulting from coupling a qubit and a resonator via a Josephson junction. Furthermore, by adding a capacitive coupling in parallel to the junction, Purcell decay can be suppressed without the need for a Purcell filter. We also show that junction readout is more robust against deleterious multiphoton processes, and offers greater flexibility for resonator frequency allocation. Crucially, junction readout achieves superior performance compared to dispersive readout while maintaining similar hardware overhead. Numerical simulations show that junction readout can achieve fidelities exceeding in under ns, making it a promising alternative for superconducting qubit readout with current hardware.
References in corpus (60)
- Cavity quantum electrodynamics for superconducting electrical circuits: an architecture for quantum computation
- QuTiP 2: A Python framework for the dynamics of open quantum systems
- QuTiP: An open-source Python framework for the dynamics of open quantum systems
- Circuit Quantum Electrodynamics
- Suppressing quantum errors by scaling a surface code logical qubit
- Quantum error correction below the surface code threshold
- Approaching Unit Visibility for Control of a Superconducting Qubit with Dispersive Readout
- AC-Stark Shift and Dephasing of a Superconducting Qubit Strongly Coupled to a Cavity Field
- Fast Scalable State Measurement with Superconducting Qubits
- Qubit-photon interactions in a cavity: Measurement induced dephasing and number splitting
- Real-time quantum error correction beyond break-even
- Realizing Rapid, High-Fidelity, Single-Shot Dispersive Readout of Superconducting Qubits
- Black-box superconducting circuit quantization
- Dephasing of a superconducting qubit induced by photon noise
- Dispersive regime of circuit QED: photon-dependent qubit dephasing and relaxation rates
- Quantum trajectory approach to circuit QED: Quantum jumps and the Zeno effect
- Fast Reset and Suppressing Spontaneous Emission of a Superconducting Qubit
- Measurement-induced state transitions in a superconducting qubit: Beyond the rotating wave approximation
- Fast quantum non-demolition readout from longitudinal qubit-oscillator interaction
- Heralded state preparation in a superconducting qubit
- Protocols for optimal readout of qubits using a continuous quantum nondemolition measurement
- Photon Shot Noise Dephasing in the Strong-Dispersive Limit of Circuit QED
- Fast readout and reset of a superconducting qubit coupled to a resonator with an intrinsic Purcell filter
- A superconducting qubit with Purcell protection and tunable coupling
- Improved Superconducting Qubit Readout by Qubit-Induced Nonlinearities
- Using a qubit to measure photon number statistics of a driven, thermal oscillator
- Removing leakage-induced correlated errors in superconducting quantum error correction
- Kerr-free three-wave mixing in superconducting quantum circuits
- Rapid Driven Reset of a Qubit Readout Resonator
- Dynamics of Transmon Ionization
- Overcoming leakage in scalable quantum error correction
- Non-linear dispersive regime of cavity QED: The dressed dephasing model
- Effect of higher-order nonlinearities on amplification and squeezing in Josephson parametric amplifiers
- Measurement-Induced State Transitions in a Superconducting Qubit: Within the Rotating Wave Approximation
- Blackbox Quantization of Superconducting Circuits using exact Impedance Synthesis
- Fast high fidelity quantum non-demolition qubit readout via a non-perturbative cross-Kerr coupling
- General method for extracting the quantum efficiency of dispersive qubit readout in circuit QED
- Adequacy of Si:P Chains as Fermi-Hubbard Simulators
- Measurement-Induced Transmon Ionization
- Leakage detection for a transmon-based surface code
- Quantum Error Correction of Qudits Beyond Break-even
- Enhancing Dispersive Readout of Superconducting Qubits Through Dynamic Control of the Dispersive Shift: Experiment and Theory
- All-microwave leakage reduction units for quantum error correction with superconducting transmon qubits
- A hardware-efficient leakage-reduction scheme for quantum error correction with superconducting transmon qubits
- Simple Impedance Response Formulas for the Dispersive Interaction Rates in the Effective Hamiltonians of Low Anharmonicity Superconducting Qubits
- Engineering Purely Nonlinear Coupling with the Quarton
- Multiport Impedance Quantization
- Optimal post-processing for a generic single-shot qubit readout
- Fast Flux-Activated Leakage Reduction for Superconducting Quantum Circuits
- Fast multiplexed superconducting qubit readout with intrinsic Purcell filtering
- Benchmarking the readout of a superconducting qubit for repeated measurements
- Ultrafast QND measurements based on diamond-shape artificial atom
- Native approach to controlled-Z gates in inductively coupled fluxonium qubits
- Optimization of the resonator-induced phase gate for superconducting qubits
- Optimal control in large open quantum systems: the case of transmon readout and reset
- 99.9%-fidelity in measuring a superconducting qubit
- Toolbox for nonreciprocal dispersive models in circuit QED
- Efficient decoupling of a non-linear qubit mode from its environment
- Impact of Josephson junction array modes on fluxonium readout
- Robustness of longitudinal transmon readout to ionization