基于超导铝的低损耗共面波导谐振器

Low loss superconducting coplanar waveguide resonator based on aluminum film

研制具有实用价值的超导量子系统需要进一步提高量子比特的质量,目前材料及核心表界面缺陷是限制量子比特相干时间的重要因素。微波谐振器作为超导量子芯片的重要组成部分,可用于表征材料质量及相关器件制备工艺优劣。利用分子束外延(MBE)技术在本征硅(111)衬底上生长铝膜,制备λ/4共面波导谐振器。通过硅衬底的处理和高质量铝薄膜的制备,在20 mK的温度和近单光子探测功率下将谐振器本征品质因子提升到10^(6)。

To develop useful superconducting quantum systems,the quality of qubits needs to be improved furthermore.At present,defects in materials and their interfaces are important factors affecting the coherence time of qubits.As an important part of superconducting quantum chip,microwave resonator can be used to characterize the quality of materials and the fabrication process of devices.Using molecular beam epitaxy technology,aluminum is deposited on intrinsic silicon(111)substrate to prepare the λ/4 coplanar waveguide resonators.By the preparation of silicon substrate and the deposition of high quality aluminum films,the intrinsic quality factor of the resonator is improved to 10^(6) at 20 mK with the probing power at near single-photon level.