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arXiv · 2502.19927

Low crosstalk modular flip-chip architecture for coupled superconducting qubits

Soeren Ihssen·Simon Geisert·Gabriel Jauma·Patrick Winkel·Martin Spiecker·Nicolas Zapata·Nicolas Gosling·Patrick Paluch·Manuel Pino·Thomas Reisinger·Wolfgang Wernsdorfer·Juan Jose Garcia-Ripoll·Ioan M. Pop
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Abstract

We present a flip-chip architecture for an array of coupled superconducting qubits, in which circuit components reside inside individual microwave enclosures. In contrast to other flip-chip approaches, the qubit chips in our architecture are electrically floating, which guarantees a simple, fully modular assembly of capacitively coupled circuit components such as qubit, control, and coupling structures, as well as reduced crosstalk between the components. We validate the concept with a chain of three nearest neighbor coupled generalized flux qubits in which the center qubit acts as a frequency-tunable coupler. Using this coupler, we demonstrate a transverse coupling on/off ratio $\approx$ 50, zz-crosstalk $\approx$ 0.7 kHz between resonant qubits and isolation between the qubit enclosures > 60 dB.

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Soeren Ihssen, Simon Geisert, Gabriel Jauma, Patrick Winkel, Martin Spiecker, Nicolas Zapata, Nicolas Gosling, Patrick Paluch, Manuel Pino, Thomas Reisinger, Wolfgang Wernsdorfer, Juan Jose Garcia-Ripoll, Ioan M. Pop. 2025-02-27. Low crosstalk modular flip-chip architecture for coupled superconducting qubits. https://doi.org/10.1063/5.0245667

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