Qiu Junling, Sun Huihui, Hu Yibin, Wang Shuya, Han Chuanbing, Shan Zheng
State Key Laboratory of Mathematical Engineering and Advanced Computing, Zhengzhou 450001, China.
Hongzhiwei Technology (Shanghai) Co., Ltd., Shanghai 200120, China.
Nanomaterials (Basel). 2023 Jan 29;13(3):542. doi: 10.3390/nano13030542.
All-nitride Josephson junctions are being actively explored for applications in superconducting quantum chips because of their unique advantages including their antioxidant chemical stability and high crystal quality. However, the theoretical research on their microstructure mechanism that determines transport properties is still absent, especially on the defects. In this paper, we apply the first principles and non-equilibrium Green's function to calculate the electrical transport characteristics of the yellow preset model. It is first revealed that the N-vacancy defects play a crucial role in determining the conductivity of the NbN-based Josephson junctions, and demonstrate the importance for the uniformity of vacancy distribution. It is found that the uniform number of vacancies can effectively increase the conductance of Josephson junction, but the position distribution of vacancies has little effect on the conductance. The work clarifies the effect of the N-vacancy defects on the conductivity of the NbN-based Josephson junctions, which offers useful guidance for understanding the microscope mechanism of the NbN-based Josephson junction, thus showing a great prospect in the improvement of the yield of superconducting quantum chips in the future.
全氮化物约瑟夫森结因其独特优势，包括抗氧化化学稳定性和高晶体质量，正被积极探索用于超导量子芯片。然而，关于决定其输运性质的微观结构机制，尤其是缺陷方面的理论研究仍然缺乏。本文应用第一性原理和非平衡格林函数来计算黄色预设模型的电输运特性。首次揭示了氮空位缺陷在决定基于氮化铌的约瑟夫森结的电导率方面起着关键作用，并证明了空位分布均匀性的重要性。发现均匀的空位数量可以有效提高约瑟夫森结的电导，但空位的位置分布对电导影响很小。这项工作阐明了氮空位缺陷对基于氮化铌的约瑟夫森结电导率的影响，为理解基于氮化铌的约瑟夫森结的微观机制提供了有用的指导，从而在未来提高超导量子芯片的产量方面展现出巨大前景。
