Transition from tunneling regime to local point contact realized on Ba0.6K0.4Fe2As2 surface

doi:10.1088/1674-1056/26/6/067402

Abstract

Using scanning tunneling spectroscopy, we studied the transition from tunneling regime to local point contact on the iron-based superconductor Ba_0.6K_0.4Fe₂As₂. By gradually reducing the junction resistance, a series of spectra were obtained with the characteristics evolving from single-particle tunneling into Andreev reflection. The spectra can be well fitted to the modified Blonder-Tinkham-Klapwijk (BTK) model and exhibit significant changes of both spectral broadening and orbital selection due to the formation of point contact. The spatial resolution of the point contact was estimated to be several nanometers, providing a unique way to study the inhomogeneity of unconventional superconductors on such a scale.

Keywords: iron-based superconductor tunneling spectra point contact spectra

Received: 06 March 2017
Revised: 21 March 2017
Accepted manuscript online:

PACS:	74.45.+c	(Proximity effects; Andreev reflection; SN and SNS junctions)
	74.50.+r	(Tunneling phenomena; Josephson effects)
	74.70.Xa	(Pnictides and chalcogenides)
	74.81.-g	(Inhomogeneous superconductors and superconducting systems, including electronic inhomogeneities)

Fund:

Project supported by the National Natural Science Foundation of China (Grant Nos. 11574372 and 11322432) and the "Strategic Priority Research Program (B)" of the Chinese Academy of Sciences (Grant No. XDB07020300).

Corresponding Authors: Lei Shan
E-mail: lshan@iphy.ac.cn

Cite this article:

Xingyuan Hou(侯兴元), Yunyin Jie(揭云印), Jing Gong(巩靖), Bing Shen(沈冰), Hai Zi(子海), Chunhong Li(李春红), Cong Ren(任聪), Lei Shan(单磊) Transition from tunneling regime to local point contact realized on Ba_0.6K_0.4Fe₂As₂ surface 2017 Chin. Phys. B 26 067402

[1]	Fischer Ø, Kugler M, Maggio-Aprile I, Berthod C and Renner C 2007 Rev. Mod. Phys. 79 353
[2]	Hoffman J E 2011 Reports on Progress in Physics 74 12
[3]	Andreev A F 1965 Sov. Phys. JETP 20 1490
[4]	Blonder G E, Tinkham M and Klapwijk T M 1982 Phys. Rev. B 25 4515
[5]	Blonder G E and Tinkham M 1983 Phys. Rev. B 27 112
[6]	Deutscher G 2005 Rev. Mod. Phys 77 109
[7]	Daghero D, Tortello M, Ummarino G A and Gonnelli R S 2011 Rep. Progr. Phys. 74 124509
[8]	Zhu J, Wang Z S, Wang Z Y, Hou X Y, Luo H Q, Lu X Y, Li C H, Shan L, Wen H H and Ren C 2015 Chin. Phys. Lett. 32 077401
[9]	Naidyuk Y G and Yanson I K 2005 Point-contact spectroscopy ( New York: Springer-Verlag) pp. 41-46, ISBN 978-0-387-21235-7
[10]	Park W K and Greene L H 2006 Rev. Sci. Instrum. 77 023905
[11]	Groll N, Pellin M J, Zasadzinksi J F and Proslier T 2015 Rev. Sci. Instrum. 86 095111
[12]	Bobrov N L, Khotkevich A V, Kamarchuk G V and Chubov P N 2014 Low Temp. Phys. 40 215
[13]	Zeljkovic I and Hoffman J E 2013 Phys. Chem. Chem. Phys. 15 13462
[14]	Gimzewski J K and Möller R 1987 Phys. Rev. B 36 1284
[15]	Rodrigo J G, García-Martín A, Sáenz J J and Vieira S 2002 Phys. Rev. Lett. 88 246801
[16]	Sun Y, Mortensen H, Schär S, Lucier A, Miyahara Y, Grütter P and Hofer W 2005 Phys. Rev. B 71 193407
[17]	Néel N, Kröger J, Limot L and Berndt R 2006 Nanotechnology 18 044027
[18]	Tartaglini E, Verhagen T G A, Galli F, Trouwborst M L, Müller R, Shiota T, Aarts J and van Ruitenbeek J M 2013 Low Temperature Physics 39 189
[19]	Agraït N, Rodrigo J G and Vieira S 1992 Phys. Rev. B 46 5814
[20]	Chuang C S and Chen T T 1996 Physica C 265 89
[21]	Martinez-Samper P, Rodrigo J G, Agrait N, Grande R and Vieira S 2000 Physica C 332 450
[22]	Luo H Q, Wang Z S, Yang H, Cheng P, Zhu X Y and Wen H H 2008 Supercond. Sci. Technol. 21 125014
[23]	Gong J, Hou X Y, Zhu J, Jie Y Y, Gu Y D, Shen B, Ren C, Li C H and Shan L 2015 Chin. Phys. B 24 077402
[24]	Shan L, Wang Y L, Gong J, Shen B, Huang Y, Yang H, Ren C and Wen H H 2011 Phys. Rev. B 83 060510
[25]	Song C L, Wang Y L, Cheng P, Jiang Y P, Li W, Zhang T, Li Z, He K, Wang L L, Jia J F, Hung H H, Wu C J, Ma X C, Chen X and Xue Q K 2011 Science 332 1410
[26]	Yin J X, Wu Z, Wang J H, Ye Z Y, Gong J, Hou X Y, Shan L, Li A, Liang X J, Wu X X, Li J, Ting C S, Wang Z Q, Hu J P, Hor P H, Ding H and Pan S H 2015 Nat. Phys. 11 543
[27]	Fan Q, Zhang W H, Liu X, Yan Y J, Ren M Q, Peng R, Xu H C, Xie B P, Hu J P, Zhang T and Feng D L 2015 Nat. Phys. 11 946
[28]	Shan L, Wang Y L, Shen B, Zeng B, Huang Y, Li A, Wang D, Yang H, Ren C, Wang Q H, Pan S H and Wen H H 2011 Nat. Phys. 7 325
[29]	Shan L, Gong J, Wang Y L, Shen B, Hou X Y, Ren C, Li C H, Yang H, Wen H H, Li S L and Dai P C 2012 Phys. Rev. Lett. 108 227002
[30]	Landauer R 1957 IBM J. Res. Dev. 1 223
[31]	Büttiker M 1986 Phys. Rev. Lett. 57 1761
[32]	Keijsers R J P, Shklyarevskii O I and van Kempen H 1996 Phys. Rev. Lett. 77 3411
[33]	Wei J, Sheet G and Chandrasekhar V 2010 Appl. Phys. Lett. 97 062507
[34]	Sharvin Y V 1964 Sov. Phys. JETP 21 655
[35]	Wang Z S, Luo H Q, Ren C and Wen H H 2008 Phys. Rev. B 78 140501
[36]	Ren C, Wang Z S, Luo H Q, Yang H, Shan L and Wen H H Phys. Rev. Lett. 101 257006
[37]	Pleceník A, Grajcar M, Beňačka Š, Seidel P and Pfuch A 1994 Phys. Rev. B 49 10016
[38]	Tanaka Y and Kashiwaya S 1995 Phys. Rev. Lett. 74 3451
[39]	Naidyuk Y G, Löhneysen H V and Yanson I K 1996 Phys. Rev. B 54 16077
[40]	Slobodzian E V, Smith C W and Dolan P J 2002 Physica C 382 401
[41]	Ciraci S and Tekman E 1989 Phys. Rev. B 40 11969
[42]	Srikanth H and Raychaudhuri A K 1992 Phys. Rev. B 46 14713
[43]	Ding H, Nakayama K, Richard P, Souma S, Sato T, Takahashi T, Neupane M, Xu Y M, Pan Z H, Fedorov A V, Wang Z, Dai X, Fang Z, Chen G F, Luo J L and Wang N L 2011 J. Phys. 23 135701
[44]	Zhao L, Liu H Y, Zhang W T, Meng J Q, Jia X W, Liu G D, Dong X L, Chen G F, Luo J L, Wang N L, Lu W, Wang G L, Zhou Y, Zhu Y, Wang X Y, Xu Z Y, Chen C T and Zhou X J 2008 Chin. Phys. Lett. 25 61

[1]	Focused-ion-beam assisted technique for achieving high pressure by uniaxial-pressure devices Di Liu(刘迪), Xingyu Wang(王兴玉), Zezhong Li(李泽众), Xiaoyan Ma(马肖燕), and Shiliang Li(李世亮). Chin. Phys. B, 2023, 32(4): 047401.
[2]	Josephson vortices and intrinsic Josephson junctions in the layered iron-based superconductor Ca₁₀(Pt₃As₈)((Fe_0.9Pt_0.1)₂As₂)₅ Qiang-Tao Sui(随强涛) and Xiang-Gang Qui(邱祥冈). Chin. Phys. B, 2022, 31(9): 097403.
[3]	Exploring Majorana zero modes in iron-based superconductors Geng Li(李更), Shiyu Zhu(朱诗雨), Peng Fan(范朋), Lu Cao(曹路), and Hong-Jun Gao(高鸿钧). Chin. Phys. B, 2022, 31(8): 080301.
[4]	Growth and characterization of superconducting Ca_1-xNa_xFe₂As₂ single crystals by NaAs-flux method Hong-Lin Zhou(周宏霖), Yu-Hao Zhang(张与豪), Yang Li(李阳), Shi-Liang Li(李世亮), Wen-Shan Hong(洪文山), and Hui-Qian Luo(罗会仟). Chin. Phys. B, 2022, 31(11): 117401.
[5]	Revealing the A_1g-type strain effect on superconductivity and nematicity in FeSe thin flake Zhaohui Cheng(程朝晖), Bin Lei(雷彬), Xigang Luo(罗习刚), Jianjun Ying(应剑俊), Zhenyu Wang(王震宇), Tao Wu(吴涛), and Xianhui Chen(陈仙辉). Chin. Phys. B, 2021, 30(9): 097403.
[6]	Nodal superconducting gap in LiFeP revealed by NMR: Contrast with LiFeAs A F Fang(房爱芳), R Zhou(周睿), H Tukada, J Yang(杨杰), Z Deng(邓正), X C Wang(望贤成) , C Q Jin(靳常青), and Guo-Qing Zheng(郑国庆). Chin. Phys. B, 2021, 30(4): 047403.
[7]	Dispersion of neutron spin resonance mode in Ba_0.67K_0.33Fe₂As₂ Tao Xie(谢涛), Chang Liu(刘畅), Tom Fennell, Uwe Stuhr, Shi-Liang Li(李世亮), and Hui-Qian Luo(罗会仟). Chin. Phys. B, 2021, 30(12): 127402.
[8]	Superconductivity at 44.4 K achieved by intercalating EMIM⁺ into FeSe Jinhua Wang(王晋花), Qing Li(李庆), Wei Xie(谢威), Guanyu Chen(陈冠宇), Xiyu Zhu(祝熙宇), and Hai-Hu Wen(闻海虎). Chin. Phys. B, 2021, 30(10): 107402.
[9]	Anomalous spectral weight transfer in the nematic state of iron-selenide superconductor C Cai(蔡淙), T T Han(韩婷婷), Z G Wang(王政国), L Chen(陈磊), Y D Wang(王宇迪), Z M Xin(信子鸣), M W Ma(马明伟), Yuan Li(李源), Y Zhang(张焱). Chin. Phys. B, 2020, 29(7): 077401.
[10]	NMR and NQR studies on transition-metal arsenide superconductors LaRu₂As₂, KCa₂Fe₄As₄F₂, and A₂Cr₃As₃ Jun Luo(罗军), Chunguang Wang(王春光) Zhicheng Wang(王志成), Qi Guo(郭琦), Jie Yang(杨杰), Rui Zhou(周睿), K Matano, T Oguchi, Zhian Ren(任治安), Guanghan Cao(曹光旱), Guo-Qing Zheng(郑国庆). Chin. Phys. B, 2020, 29(6): 067402.
[11]	Electronic structure and spatial inhomogeneity of iron-based superconductor FeS Chengwei Wang(王成玮), Meixiao Wang(王美晓), Juan Jiang(姜娟), Haifeng Yang(杨海峰), Lexian Yang(杨乐仙), Wujun Shi(史武军), Xiaofang Lai(赖晓芳), Sung-Kwan Mo, Alexei Barinov, Binghai Yan(颜丙海), Zhi Liu(刘志), Fuqiang Huang(黄富强), Jinfeng Jia(贾金峰), Zhongkai Liu(柳仲楷), Yulin Chen(陈宇林). Chin. Phys. B, 2020, 29(4): 047401.
[12]	Evidence for bosonic mode coupling in electron dynamics of LiFeAs superconductor Cong Li(李聪), Guangyang Dai(代光阳), Yongqing Cai(蔡永青), Yang Wang(王阳), Xiancheng Wang(望贤成), Qiang Gao(高强), Guodong Liu(刘国东), Yuan Huang(黄元), Qingyan Wang(王庆艳), Fengfeng Zhang(张丰丰), Shenjin Zhang(张申金), Feng Yang(杨峰), Zhimin Wang(王志敏), Qinjun Peng(彭钦军), Zuyan Xu(许祖彦), Changqing Jin(靳常青), Lin Zhao(赵林)†, and X J Zhou(周兴江)‡. Chin. Phys. B, 2020, 29(10): 107402.
[13]	Nonlinear uniaxial pressure dependence of the resistivity in Sr_1-xBa_xFe_1.97Ni_0.03As₂ Hui-Can Mao(毛慧灿), Dong-Liang Gong(龚冬良), Xiao-Yan Ma(马肖燕), Hui-Qian Luo(罗会仟), Yi-Feng Yang(杨义峰), Lei Shan(单磊), Shi-Liang Li(李世亮). Chin. Phys. B, 2018, 27(8): 087402.
[14]	Electronic structure and nematic phase transition in superconducting multiple-layer FeSe films grown by pulsed laser deposition method Bing Shen(沈兵), Zhong-Pei Feng(冯中沛), Jian-Wei Huang(黄建伟), Yong Hu(胡勇), Qiang Gao(高强), Cong Li(李聪), Yu Xu(徐煜), Guo-Dong Liu(刘国东), Li Yu(俞理), Lin Zhao(赵林), Kui Jin(金魁), X J Zhou(周兴江). Chin. Phys. B, 2017, 26(7): 077402.
[15]	Comparison of band structure and superconductivity in FeSe_0.5Te_0.5 and FeS Yang Yang(杨阳), Shi-Quan Feng(冯世全), Yuan-Yuan Xiang(向圆圆), Hong-Yan Lu(路洪艳), Wan-Sheng Wang(王万胜). Chin. Phys. B, 2017, 26(12): 127401.

No Suggested Reading articles found!

Viewed

Full text

Abstract

Cited

Metrics
Related Articles

Transition from tunneling regime to local point contact realized on Ba0.6K0.4Fe2As2 surface

Cite this article:

Online attention

Transition from tunneling regime to local point contact realized on Ba_0.6K_0.4Fe₂As₂ surface