Fabrication and characterization of superconducting multiqubit device with niobium base layer  

作　　者：Feifan Su Zhaohua Yang Shoukuan Zhao Haisheng Yan Ziting Wang Xiaohui Song Ye Tian Shiping Zhao 宿非凡;杨钊华;赵寿宽;严海生;王子婷;宋小会;田野;赵士平(Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100190,China;Chinese Academy of Sciences Center for Excellence in Topological Quantum Computation,University of Chinese Academy of Sciences,Beijing 100190,China;Songshan Lake Materials Laboratory,Dongguan 523808,China)

机构地区：[1]Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China [2]School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100190,China [3]Chinese Academy of Sciences Center for Excellence in Topological Quantum Computation,University of Chinese Academy of Sciences,Beijing 100190,China [4]Songshan Lake Materials Laboratory,Dongguan 523808,China

出　　处：《Chinese Physics B》2021年第10期138-142,共5页中国物理B（英文版）

基　　金：supported by the National Key R&D Program of China(Grant No.2016YFA0300601);the National Natural Science Foundation of China(Grant Nos.11934018 and 11874063);the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB28000000);the Key-Area Research and Development Program of GuangDong Province,China(Grant No.2018B030326001)。

摘　　要：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 a niobium base layer,shadow-evaporated Josephson junctions,and airbridges across the qubit control lines to suppress crosstalk.Our results show that these multiqubit devices have well-characterized readout resonators,and that the energy relaxation and Ramsey(spin-echo)dephasing times are up to∼40µs and 14(47)µs,respectively.We perform single-qubit gate operations that 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 in qubit coherence performance using this fabrication process are also discussed.

关 键 词：superconducting quantum computing transmon qubit device fabrication CHARACTERIZATION 

分 类 号：O413[理学—理论物理]