Weak link nanobridges as single flux quantum elements
Weak link nanobridges as single flux quantum elements
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DOI：
10.1088/1361-6668/aa80cd
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发表时间：
2017-09-01
影响因子：
3.6
通讯作者：
Williams, Jonathan M.
中科院分区：
文献类型：
--
作者：
Shelly, Connor D.;See, Patrick;Williams, Jonathan M.
本文研究了使用弱连接纳米桥作为约瑟夫森结元件用于创建约瑟夫森电路的可行性。我们展示了一个单步电子束光刻过程的发展，制造尺寸下降到40 nm × 100 nm的铌纳米桥。单步工艺有利于制造，可扩展到需要许多结的复杂电路。我们测量的IV-特性（IVC）的纳米桥之间的温度为4.2和9 K，并找到协议与数值模拟和分析的反向分流结（RSJ）模型。此外，我们研究了射频照射下的纳米桥的行为，并观察到特征微波诱导Shapiro步骤。我们使用RSJ模型和电路模拟器JSIM模拟射频辐照下的IVC与实验数据一致。作为一个潜在的使用纳米桥在电路中需要许多结，我们研究了基于纳米桥的约瑟夫森比较器电路使用JSIM的理论性能。
This paper investigates the feasibility of using weak link nanobridges as Josephson junction elements for the purpose of creating Josephson circuits. We demonstrate the development of a single-step electron beam lithography procedure to fabricate niobium nanobridges with dimensions down to 40 nm x 100 nm. The single-step process facilitates fabrication that is scalable to complex circuits that require many junctions. We measure the IV-characteristics (IVC) of the nanobridges between temperatures of 4.2 and 9 K and find agreement with numerical simulations and the analytical resistively shunted junction (RSJ) model. Furthermore, we investigate the behaviour of the nanobridges under rf irradiation and observe the characteristic microwave-induced Shapiro steps. Our simulated IVC under rf irradiation using both the RSJ model and circuit simulator JSIM are in agreement with the experimental data. As a potential use of nanobridges in circuits requiring many junctions, we investigate the theoretical performance of a nanobridge-based Josephson comparator circuit using JSIM.