Authors: Ihssen, Soeren; Geisert, Simon; Jauma, Gabriel; Winkel, Patrick; Spiecker, Martin; Zapata, Nicolas; Gosling, Nicolas; Paluch, Patrick; Pino, Manuel; Reisinger, Thomas; Wernsdorfer, Wolfgang; Garcia-Ripoll, Juan Jose; Pop, Ioan M.
Journal: APPLIED PHYSICS LETTERS
Publication date: 2025/03/01
DOI: 10.1063/5.0245667
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 approximate to 50, zz-crosstalk approximate to 0.7 kHz between resonant qubits and isolation between the qubit enclosures >60 dB.
