Modulation depth of series SQUIDs modified by Josephson junction area<sup>

Modulation depth of series SQUIDs modified by Josephson junction area

Liu Jie¹, Gao He^{2, 3}, Li Gang¹, Wei Li Zheng², Ahmada Kamal¹, Ying Shan Zhang¹, Liu Jian She¹, Chen Wei^{1, †}

(color online) (a) SEM photographs of fabricated series SQUID amplifiers with different junction areas. The detailed structure and practical junction area corresponding to the red circle in each SQUID: (b) 22.5 μm², (c) 15.9 μm², (d) 8.2 μm², (e) 5.3 μm².