Investigation of dimensionality in superconducting NbN thin film samples with different thicknesses and NbTiN meander nanowire samples by measuring the upper critical field

作     者：Mudassar Nazir 杨晓燕 田焕芳 宋鹏涛 王战 相忠诚 郭学仪 金贻荣 尤立星 郑东宁 Mudassar Nazir;Xiaoyan Yang;Huanfang Tian;Pengtao Song;Zhan Wang;Zhongcheng Xiang;Xueyi Guo;Yirong Jin;Lixing You;Dongning Zheng

作者机构：Institute of Physics and Beijing National Laboratory for Condensed Matter PhysicsChinese Academy of SciencesBeijing 100190China University of Chinese Academy of SciencesBeijing 100190China State Key Laboratory of Functional Materials for InformaticsShanghai Institute of Microsystem and Information Technology and the Center for Excellence in Superconducting ElectronicsChinese Academy of SciencesShanghai 200050China Songshan Lake Materials LaboratoryDongguan 523808China 

出 版 物：《Chinese Physics B》 (中国物理B（英文版）)

年 卷 期：2020年第29卷第8期

页      面：457-464页

核心收录：

学科分类：080705[工学-制冷及低温工程] 07[理学] 070205[理学-凝聚态物理] 08[工学] 0807[工学-动力工程及工程热物理] 0805[工学-材料科学与工程（可授工学、理学学位）] 0704[理学-天文学] 0702[理学-物理学] 

基　　金：the Chinese Academy of Sciences(Grant No.XDB25000000) 

主　　题：NbN micro-bridges and NbTiN meander nanowire upper critical field low dimensionality anisotropic magneto-resistance 

摘      要：We study superconducting properties of NbN thin film samples with different thicknesses and an ultra-thin NbTiN meander nanowire *** the ultra-thin samples,we found that the temperature dependence of upper critical field(Hc2)in parallel to surface orientation shows bending curvature close to critical temperature Tc,suggesting a two-dimensional(2D)nature of the *** 2D behavior is further supported by the angular dependence measurements of Hc2 for the thinnest *** temperature dependence of parallel upper critical field for the thick films could be described by a model based on the anisotropic Ginzburg-Landau ***,the results measured in the field perpendicular to the film surface orientation show a similar bending curvature but in a much narrow temperature region close to Tc for the ultra-thin *** suggest that this feature could be due to suppression of pair-breaking caused by local *** further propose the temperature dependence of perpendicular Hc2 as a measure of uniformity of superconducting ultra-thin *** the thick samples,we find that Hc2 shows maxima for both parallel and perpendicular *** Hc2 peak for the perpendicular orientation is believed to be due to the columnar structure formed during the growth of the thick *** presence of columnar structure is confirmed by transmission electron microscopy(TEM).In addition,we have measured the angular dependence of magneto-resistance,and the results are consistent with the Hc2 data.