Single Flux Quantum-Based Digital Control of Superconducting Qubits in a Multi-Chip Module

Abstract

The single flux quantum (SFQ) digital superconducting logic family has been proposed for the scalable control of next-generation superconducting qubit arrays. In the initial implementation, SFQ-based gate fidelity was limited by quasiparticle (QP) poisoning induced by the dissipative on-chip SFQ driver circuit. In this work, we introduce a multi-chip module architecture to suppress phonon-mediated QP poisoning. Here, the SFQ elements and qubits are fabricated on separate chips that are joined with In bump bonds. We use interleaved randomized benchmarking to characterize the fidelity of SFQ-based gates, and we demonstrate an error per Clifford gate of 1.2(1)%, an order-of-magnitude reduction over the gate error achieved in the initial realization of SFQ-based qubit control. We use purity benchmarking to quantify the contribution of incoherent error at 0.96(2)%; we attribute this error to photon-mediated QP poisoning mediated by the resonant mm-wave antenna modes of the qubit and SFQ-qubit coupler. We anticipate that a straightforward redesign of the SFQ driver circuit to limit the bandwidth of the SFQ pulses will eliminate this source of infidelity, allowing SFQ-based gates with fidelity approaching theoretical limits, namely 99.9% for resonant sequences and 99.99% for more complex pulse sequences involving variable pulse-to-pulse separation.

arXiv comment15 pages, 8+4 figures, 1 table

References in corpus (43)

• Supplementary information for "Quantum supremacy using a programmable superconducting processor"
• Surface codes: Towards practical large-scale quantum computation
• Logic gates at the surface code threshold: Superconducting qubits poised for fault-tolerant quantum computing
• Randomized Benchmarking of Quantum Gates
• A Theory of Fault-Tolerant Quantum Computation
• Realizing Repeated Quantum Error Correction in a Distance-Three Surface Code
• Efficient measurement of quantum gate error by interleaved randomized benchmarking
• Engineering cryogenic setups for 100-qubit scale superconducting circuit systems
• Realizing Rapid, High-Fidelity, Single-Shot Dispersive Readout of Superconducting Qubits
• Realization of an Error-Correcting Surface Code with Superconducting Qubits
• Correlated Charge Noise and Relaxation Errors in Superconducting Qubits
• Microwave Quantum Link between Superconducting Circuits Housed in Spatially Separated Cryogenic Systems
• Optimal quantum control using randomized benchmarking
• Measurement and Control of Quasiparticle Dynamics in a Superconducting Qubit
• Impact of ionizing radiation on superconducting qubit coherence
• Hot non-equilibrium quasiparticles in transmon qubits
• Implementing optimal control pulse shaping for improved single-qubit gates
• Control and readout of a superconducting qubit using a photonic link
• Beyond Moore's technologies: operation principles of a superconductor alternative
• Quasiparticle dynamics in granular aluminum close to the superconductor to insulator transition
• Estimating the Coherence of Noise
• Quantum--Classical Interface Based on Single Flux Quantum Digital Logic
• Suppressing relaxation in superconducting qubits by quasiparticle pumping
• The QICK (Quantum Instrumentation Control Kit): Readout and control for qubits and detectors
• Digital coherent control of a superconducting qubit
• Decoherence of superconducting qubits caused by quasiparticle tunneling
• Measurement of a Superconducting Qubit with a Microwave Photon Counter
• Qubit metrology of ultralow phase noise using randomized benchmarking
• Phonon-Mediated Quasiparticle Poisoning of Superconducting Microwave Resonators
• Bifluxon: Fluxon-Parity-Protected Superconducting Qubit
• Engineering superconducting qubits to reduce quasiparticles and charge noise
• Phonon downconversion to suppress correlated errors in superconducting qubits
• Optimal Qubit Control Using Single-Flux Quantum Pulses
• Photon-assisted charge-parity jumps in a superconducting qubit
• Bogoliubov Quasiparticles in Superconducting Qubits
• Scalable Hardware-Efficient Qubit Control with Single Flux Quantum Pulse Sequences
• Distinguishing parity-switching mechanisms in a superconducting qubit
• High-Fidelity Measurement of a Superconducting Qubit using an On-Chip Microwave Photon Counter
• Efficient quasiparticle traps with low dissipation through gap engineering
• Reversible Fluxon Logic: Topological particles allow ballistic gates along 1D paths
• Using materials for quasiparticle engineering
• Flexible Coaxial Ribbon Cable for High-Density Superconducting Microwave Device Arrays
• Reversible Fluxon Logic with optimized CNOT gate components

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• A cryogenic on-chip microwave pulse generator for large-scale superconducting quantum computing
• Coherence-limited digital control of a superconducting qubit using a Josephson pulse generator at 3 K
• Quasiparticle Dynamics in Superconducting Quantum-Classical Hybrid Circuits
• Sub-Harmonic Control of a Fluxonium Qubit via a Purcell-Protected Flux Line
• Nonvolatile Cryogenic Phase Slip Memory with Single-Shot Readout
• Overhead in Quantum Circuits with Time-Multiplexed Qubit Control
• Enhanced superconductivity in atomically thin noble metals: From quantum confinement to interface-induced Lifshitz transition
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