| Popis: |
Superconducting transmon qubits are the leading platform in solid-state quantum computing and quantum simulation applications. In this work, we develop a fabrication process for the transmon multiqubit device with niobium base layers, shadow evaporated Josephson junctions, and airbridges across the qubit control lines to suppress crosstalk. Our results show that the multiqubit devices have well-characterized readout resonators, and the energy relaxation and Ramsey (spin-echo) dephasing times up to ~40 μs and 14 (47) μs, respectively. We perform single-qubit gate operations which demonstrate a maximum gate fidelity of 99.97%. In addition, two-qubit vacuum Rabi oscillations are measured to evaluate the coupling strength between qubits, and the crosstalk among qubits is found to be less than 1% with the fabricated airbridges. Further improvements of the qubit coherence performance using the present fabrication process will be discussed. |
