Characteristics of focused ion beam nanoscale Josephson devices
Characteristics of focused ion beam nanoscale Josephson devices
复制标题
聚焦离子束纳米约瑟夫森装置的特点
DOI：
10.1088/0953-2048/22/6/064011
复制
发表时间：
2009
影响因子：
3.6
通讯作者：
J. Gallop
中科院分区：
文献类型：
--
作者：
L. Hao;D. Cox;J. Gallop
量子计量学和纳米科学的要求正在推动对各种物理领域的单粒子探测能力的需求，包括量子信息处理，单光子探测，纳米机电系统，纳米磁学和自旋电子学。未来，被探测的单个粒子包括原子、分子、光子、自旋甚至声子。纳米级超导量子干涉器件（nanoSQUID）代表了一种古老但令人兴奋的超导技术的新表现，它解决了其中的一些要求。在本文中，我们描述了一个简单的方法来制造铌微桥弱链接使用组合的光学光刻和聚焦离子束，可用于制造nanoSQUID。该器件具有非滞后电流-电压特性，即使在4.2K以上的工作温度下，噪声也非常低。为了提高我们对约瑟夫森微桥/纳米桥结超导特性的理解，我们进行了一系列研究，约瑟夫森微桥/纳米桥结已被证明在实现低噪声纳米SQUID方面非常成功。这些包括低温电阻与温度（R（T））和电流-电压特性测量，原子力显微镜扫描，控制镓（Ga）离子铣削和注入，以及这些约瑟夫森器件和铌薄膜的离子束轨道建模。
The requirements of quantum metrology and nanoscience are driving the need for single-particle detection capability across a wide variety of physics areas, including quantum information processing, single-photon detection, nanoelectromechanical systems, nanomagnetism and spintronics. The single particles to be detected include atoms, molecules, photons, spins and even phonons, in the future. Nanoscale superconducting quantum interference devices (nanoSQUIDs) represent a new manifestation of an old but exciting superconducting technology which addresses some of these requirements. In this paper we describe a straightforward approach to fabricating Nb microbridge weak links using combined optical lithography and focused ion beams which may be used to fabricate nanoSQUIDs. The devices show non-hysteretic current–voltage characteristics and demonstrate very low noise, even at operating temperatures above 4.2 K. To improve our understanding of the superconducting properties of the Josephson microbridge/nanobridge junctions which have proved very successful in realizing low noise nanoSQUIDs we have carried out a combination of investigations. These include cryogenic resistance versus temperature (R(T)) and current–voltage characteristic measurements, atomic force microscope scans, controlled gallium (Ga) ion milling and implantation, and ion beam track modelling of these Josephson devices and Nb thin films.