Building Blocks of a Flip-Chip Integrated Superconducting Quantum Processor

Abstract

We have integrated single and coupled superconducting transmon qubits into flip-chip modules. Each module consists of two chips -- one quantum chip and one control chip -- that are bump-bonded together. We demonstrate time-averaged coherence times exceeding $90\mu s$, single-qubit gate fidelities exceeding $99.9\%$, and two-qubit gate fidelities above $98.6\%$. We also present device design methods and discuss the sensitivity of device parameters to variation in interchip spacing. Notably, the additional flip-chip fabrication steps do not degrade the qubit performance compared to our baseline state-of-the-art in single-chip, planar circuits. This integration technique can be extended to the realisation of quantum processors accommodating hundreds of qubits in one module as it offers adequate input/output wiring access to all qubits and couplers.

33 pages, 12 figures, includes supplementary materials, updated with further calculations on participation ratio and Purcell limit

References in corpus (12)

• Supplementary information for "Quantum supremacy using a programmable superconducting processor"
• Strong quantum computational advantage using a superconducting quantum processor
• Robust randomized benchmarking of quantum processes
• Decoherence benchmarking of superconducting qubits
• Quantum walks on a programmable two-dimensional 62-qubit superconducting processor
• Logical-qubit operations in an error-detecting surface code
• Analysis of parametrically driven exchange-type (iSWAP) and two-photon (bSWAP) interactions between superconducting qubits
• Simplified Josephson-junction fabrication process for reproducibly high-performance superconducting qubits
• Benchmarking the noise sensitivity of different parametric two-qubit gates in a single superconducting quantum computing platform
• High Coherence in a Tileable 3D Integrated Superconducting Circuit Architecture
• Vacuum-gap transmon qubits realized using flip-chip technology
• Realization of high-fidelity CZ gates in extensible superconducting qubits design with a tunable coupler

Cited by in corpus (11)

• Scalable High-Performance Fluxonium Quantum Processor
• Transmon qubit readout fidelity at the threshold for quantum error correction without a quantum-limited amplifier
• Long-distance transmon coupler with CZ gate fidelity above $99.8\%$
• Universal fidelity reduction of quantum operations from weak dissipation
• High-coherence superconducting qubits made using industry-standard, advanced semiconductor manufacturing
• Path toward manufacturable superconducting qubits with relaxation times exceeding 0.1 ms
• Enhancing the Coherence of Superconducting Quantum Bits with Electric Fields
• Qubit-compatible substrates with superconducting through-silicon vias
• Flip-chip-based microwave spectroscopy of Andreev bound states in a planar Josephson junction
• Shape optimization of superconducting transmon qubit for low surface dielectric loss
• Aluminum air bridges for superconducting quantum devices realized using a single step electron-beam lithography process