Quantum computers (QC), if realized, could disrupt many computationally intense fields of science. The building block element of a QC is a quantum bit (qubit). Qubits enable the use of quantum superposition and multi-state entanglement in QC calculations, allowing a QC to simultaneously perform millions of computations at once. However, quantum states stored in a qubit degrade with decreased quality factors and interactions with the environment. One technical solution to improve qubit lifetimes and network interactions is a circuit comprised of a Josephson junction-based qubit located inside of a high Q-factor superconducting 3D cavity. It is known that niobium resonators can reach $Q_{0}>10^{11}$. However, existing cavity geometries are optimized for particle acceleration rather than hosting qubits. RadiaBeam Technologies, in collaboration with Argonne National Laboratory and The University of Chicago, has developed a niobium superconducting radio frequency quarter-wave resonant cavity (QWR) for quantum computation. A 6 GHz QWR was optimized to include tapering of the inner and outer conductors, a toroidal shape for the resonator shorting plane, and an inner conductor tip to reduce parasitic capacitance. In this paper, we present the results of the resonator design optimization, fabrication, processing, and testing.

中文翻译：

---

量子信息系统具有优化形状的铌四分之一波长谐振器

如果实现了量子计算机（QC），它可能会破坏许多计算密集的科学领域。QC的基本元素是量子位（qubit）。量子位可以在QC计算中使用量子叠加和多态纠缠，从而使QC可以一次同时执行数百万次计算。但是，存储在量子位中的量子态会随着质量因数降低以及与环境的相互作用而降低。一种改善量子比特寿命和网络交互的技术解决方案是一种电路，该电路由位于高Q因子超导3D腔内部的基于约瑟夫逊结的量子比特组成。已知铌谐振器可以达到$ Q_ {0}> 10 ^ {11} $。但是，现有的腔几何形状已针对粒子加速进行了优化，而不是托管量子位。RadiaBeam Technologies，与Argonne国家实验室和芝加哥大学合作，开发了用于量子计算的铌超导射频四分之一波谐振腔（QWR）。对6 GHz QWR进行了优化，以包括内部和外部导体的锥度，谐振器短路平面的环形形状以及内部导体尖端，以减少寄生电容。在本文中，我们介绍了谐振器设计优化，制造，处理和测试的结果。内部导体尖端可减少寄生电容。在本文中，我们介绍了谐振器设计优化，制造，处理和测试的结果。内部导体尖端可减少寄生电容。在本文中，我们介绍了谐振器设计优化，制造，处理和测试的结果。