
Compact NbN resonators with high kinetic inductance
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XingYu Wei(魏兴雨), JiaZheng Pan(潘佳政), YaPeng Lu(卢亚鹏), JunLiang Jiang(江俊良), ZiShuo Li(李子硕), Sheng Lu(卢盛), XueCou Tu(涂学凑), QingYuan Zhao(赵清源), XiaoQing Jia(贾小氢), Lin Kang(康琳), Jian Chen(陈健), ChunHai Cao(曹春海), HuaBing Wang(王华兵), WeiWei Xu(许伟伟), GuoZhu Sun(孙国柱), and PeiHeng Wu(吴培亨)
Chin. Phys. B, 2020, 29 (12):
128401.
DOI: 10.1088/16741056/abc2b8
We design and fabricate Λ/2 coplanar waveguide NbN resonators, the thickness and length of which are only several nanometers and hundred microns, respectively. The quality factor of such compact resonators can reach up to 7.5×10^{4} at single photon power level at 30 mK with the resonance frequency around 6.835 GHz. In order to tune the resonant frequency, the resonator is terminated to the ground with a dcSQUID. By tuning the magnetic flux in the dcSQUID, the effective inductance of the dcSQUID is varied, which leads to the change in the resonant frequency of the resonator. The tunability range is more than 30 MHz and the quality factor is about 3×10^{3}. These compact and tunable NbN resonators have potential applications in the quantum information processing, such as in the precision measurement, coupling and/or reading out the quantum states of qubits.
