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arXiv · 2211.00143

The Quantum Socket and DemuXYZ-Based Gates with Superconducting Qubits

J. H. Béjanin·C. T. Earnest·M. Mariantoni
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Abstract

Building large-scale superconducting quantum computers requires two complimentary elements: scalable wiring techniques and multiplex architectures. In our previous work [B\'ejanin et al., Phys. Rev. Applied 6, 044010 (2016)], we have introduced and characterized a truly vertical interconnect named the quantum socket. In this paper, we exercise the quantum socket using high-coherence flux-tunable Xmon transmon qubits. In particular, we test potential qubit heating and one-qubit gate performance. We observe no heating effects and time-stable gate fidelities in excess of 99.9%. We then propose and experimentally characterize a demultiplexed gate technique based on flux pulses and a common continuous drive signal: DemuXYZ. We discuss DemuXYZ's working principle, show its operation, and perform quantum process tomography on a selection of one-qubit gates to confirm proper operation. We obtain fidelities around 93% likely limited by flux-pulse imperfections. We finally discuss future solutions for wiring integration as well as improvements to the DemuXYZ technique.

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J. H. Béjanin, C. T. Earnest, M. Mariantoni. 2022-10-31. The Quantum Socket and DemuXYZ-Based Gates with Superconducting Qubits. https://arxiv.org/abs/2211.00143

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