Скачать или смотреть INQA Conference 2025: Ioan Pop - Karlsruhe Institute of Technology

Title: Modular, crosstalk-resilient flip-chip architecture for superconducting qubits

Abstract: I present two advances toward scalable, high-fidelity
superconducting qubit architectures. First, I introduce a readout scheme
based on purely kinetic inductance coupling between a flux qubit and its
resonator, allowing independent control of dispersive shifts (60 kHz–2 MHz at the sweet spot) and enabling high state-preparation fidelities (99.7% ground, 92.7% excited) with 0.1% leakage. Second, I demonstrate a modular flip-chip design where qubits, control, and couplers reside on electrically floating chips in isolated microwave enclosures, achieving strong suppression of microwave and phonon-mediated crosstalk. In a qubit–coupler–qubit chain, we realize tunable transverse coupling with an on/off ratio of about 50, approximately 0.7 kHz zz cross-talk, and 60 dB isolation. Together, these techniques support compact, low-crosstalk quantum processors with flexible, high-fidelity readout.