标题： 用氟基表面处理提高超导量子比特性能 显示英文标题

标题： Improving Transmon Qubit Performance with Fluorine-based Surface Treatments

摘要： 减少材料和加工引起的退相干对于基于超导量子位的实用规模量子处理器的发展至关重要。 在这里，我们报告了两种基于氟的湿法蚀刻的影响，我们使用这些蚀刻来处理固定频率的transmon量子位中约瑟夫森结（JJs）下方的硅表面，这些量子位使用铝基金属化制造。 通过几种材料分析技术，我们证明这些表面处理可以去除由我们的JJs制造引入的锗残留物，而无需对整体工艺流程进行其他更改。 这些表面处理显著提高了最高性能工艺的能量退相干时间，中位数为$T_1=334~\mu$s，对应品质因数$Q=6.6\times10^6$。 这一结果表明，在集成这些表面处理之前，金属-衬底界面直接位于JJs下方，是这些transmon量子位电路中微波损耗的主要贡献者。 此外，这项工作说明了如何将材料分析与量子器件性能指标结合使用，以提高超导量子位的性能。 显示英文摘要

摘要： Reducing materials and processing-induced decoherence is critical to the development of utility-scale quantum processors based on superconducting qubits. Here we report on the impact of two fluorine-based wet etches, which we use to treat the silicon surface underneath the Josephson junctions (JJs) of fixed-frequency transmon qubits made with aluminum base metallization. Using several materials analysis techniques, we demonstrate that these surface treatments can remove germanium residue introduced by our JJ fabrication with no other changes to the overall process flow. These surface treatments result in significantly improved energy relaxation times for the highest performing process, with median $T_1=334~\mu$s, corresponding to quality factor $Q=6.6\times10^6$. This result suggests that the metal-substrate interface directly underneath the JJs was a major contributor to microwave loss in these transmon qubit circuits prior to integration of these surface treatments. Furthermore, this work illustrates how materials analysis can be used in conjunction with quantum device performance metrics to improve performance in superconducting qubits.