| CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES |
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Doping Induced Gap Anisotropy in Iron-Based Superconductors: a Point-Contact Andreev Reflection Study of BaFe2−xNixAs2 Single Crystals |
| ZHU Jun1, WANG Zhao-Sheng1, WANG Zhen-Yu1, HOU Xing-Yuan1, LUO Hui-Qian1, LU Xing-Ye1, LI Chun-Hong1, SHAN Lei1, WEN Hai-Hu2, REN Cong1** |
1National Laboratory for Superconductivity, Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190
2Department of Physics, Nanjing University, Nanjing 210093 |
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| Cite this article: |
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ZHU Jun, WANG Zhao-Sheng, WANG Zhen-Yu et al 2015 Chin. Phys. Lett. 32 077401 |
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Abstract We report a systematic investigation on c-axis point-contact Andreev reflection (PCAR) in BaFe2−xNixAs2 superconducting single crystals from underdoped to overdoped regions (0.075≤x≤0.15). At low temperatures, an in-gap sharp peak at low-bias voltage is observed in PCAR for overdoped samples, in contrast to the case of underdoped junctions, in which an in-gap plateau is observed. The variety of the conductance spectra with doping can be well described by using a generalized Blonder–Tinkham–Klapwijk formalism with an angle-dependent gap. This gap shows a clear crossover from a nodeless in the underdoped side to a nodal feature in the overdoped region. This result provides evidence of the doping-induced evolution of the superconducting order parameter when the inter-pocket and intra-pocket scattering are tuned through doping, as expected in the s± scenario.
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Received: 16 April 2015
Published: 30 July 2015
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| PACS: |
74.20.Rp
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(Pairing symmetries (other than s-wave))
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74.25.Ha
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(Magnetic properties including vortex structures and related phenomena)
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74.70.Dd
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(Ternary, quaternary, and multinary compounds)
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[1] Mazin I I, Singh D J, Johannes M D and Du M H 2008 Phys. Rev. Lett. 101 057003
[2] Wang F, Zhai H, Ran Y, Vishwanath A and Lee D H 2009 Phys. Rev. Lett. 102 047005
[3] Kuroki K, Onari S, Arita R, Usui H, Tanaka Y, Kontani H and Aoki H 2008 Phys. Rev. Lett. 101 087004
[4] Kuroki K, Usui H, Onari S, Arita R and Aoki H 2009 Phys. Rev. B 79 224511
[5] Graser S, Kemper A F, Maier T A, Cheng H P, Hirschfeld P J and Scalapino D J 2010 Phys. Rev. B 81 214503
Maier T A, Graser S, Scalapino D J and Hirschfeld P J 2009 Phys. Rev. B 79 224510
[6] Fletcher J D, Serafin A, Malone L, Analytis J G, Chu J H, Erickson A S, Fisher I R and Carrington A 2009 Phys. Rev. Lett. 102 147001
Hicks C W, Lippman T M, Huber M E, Analytis J G, Chu J H, Erickson A S, Fisher I R and Moler K A 2009 Phys. Rev. Lett. 103 127003
[7] Dong J K, Zhou S Y, Guan T Y, Zhang H, Dai Y F, Qiu X, Wang X F, He Y, Chen X H and Li S Y 2010 Phys. Rev. Lett. 104 087005
Hashimoto K, Serafin A, Tonegawa S, Katsumata R, Okazaki R, Saito T, Fukazawa H, Kohori Y, Kihou K, Lee C H, Iyo A, Eisaki H, Ikeda H, Matsuda Y, Carrington A and Shibauchi T 2010 Phys. Rev. B 82 014526
[8] Hashimoto K, Yamashita M, Kasahara S, Senshu Y, Nakata N, Tonegawa S, Ikada K, Serafin A, Carrington A, Terashima T, Ikeda H, Shibauchi T and Matsuda Y 2010 Phys. Rev. B 81 220501(R)
[9] Ding H, Richard P, Nakayama K, Sugawara K, Arakane T, Sekiba Y, Takayama A, Souma S, Sato T, Takahashi T, Wang Z, Dai X, Fang Z, Chen G F, Luo J L and Wang N L 2008 Europhys. Lett. 83 47001
[10] Wang Q Y, Li Z, Zhang W H, Zhang Z C, Zhang J S, Li W, Ding H, Ou Y B, Deng P, Chang K, Wen J, Song C L, He K, Jia J F, Ji S H, Wang Y Y, Wang L L, Chen X, Ma X C and Xue Q K 2012 Chin. Phys. Lett. 29 037402
[11] Zhang X H, Oh Y S, Liu Y, Yan L Q, Kim K H, Greene R L and Takeuchi I 2009 Phys. Rev. Lett. 102 147002
Zhang X H, Oh Y S, Liu Y, Yan L Q, Saha S R, Butch N P, Kirshenbaum K, Kim K H, Paglione J, Richard Greene L and Takeuchi I 2010 Phys. Rev. B 82 020515(R)
[12] Hardy F, Ademann P, Wolf T, Löhneysen H V and Meingast C 2009 Phys. Rev. Lett. 102 187004
[13] Reid J P, Tanatar M A, Luo X G, Shakeripour H, Doiron-Leyraud N, Ni N, Bud'ko S L, Canfield P C, Prozorov R and Taillefer L 2010 Phys. Rev. B 82 064501
[14] Prozorov R, Tanatar M A, Ni N, Kreyssig A, Nandi S, Bud'ko S L, Goldman A I and Canfield P C 2009 Phys. Rev. B 80 174517
[15] Martin C, Kim H, Gordon R T, Ni N, Kogan V G, Bud'ko S L, Canfield P C, Tanatar M A and Prozorov R 2010 Phys. Rev. B 81 060505(R)
[16] Gofryk K, Vorontsov A B, Vekhter I, Sefat A S, Imai T, Bauer E D, Thompson J D and Ronning F 2011 Phys. Rev. B 83 064513
[17] Mu G, Tang J, Tanabe Y, Xu J T, Heguri S and Tanigaki K 2011 Phys. Rev. B 84 054505
[18] Ren C, Wang Z S, Luo H Q, Yang H, Shan L and Wen H H 2008 Phys. Rev. Lett. 101 257006
[19] 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(R)
[20] Xu N, Richard P, Shi X, Roekeghem A V, Qian T, Razzoli E, Rienks E, Chen G F, Ieki E, Nakayama K, Sato T, Takahashi T, Shi M and Ding H 2013 Phys. Rev. B 88 220508(R)
[21] Tafti F F, Juneau F A, Delage M, Renè de Cotret S, Reid J P, Wang A F, Luo X G, Chen X H, Doiron L N and Taillefer L 2013 Nat. Phys. 9 349
[22] Deutscher G 2005 Rev. Mod. Phys. 77 109
[23] Daghero D and Gonnelli R S 2010 Supercond. Sci. Technol. 23 043001
[24] Golubov A A, Brinkman A, Tanaka Y, Mazin I I and Dolgov O V 2009 Phys. Rev. Lett. 103 077003
Ghaemi P, Wang F and Vishwanath A 2009 Phys. Rev. Lett. 102 157002
[25] Wang D, Wan Y and Wang Q H 2009 Phys. Rev. Lett. 102 197004
Sperstad I B, Linder J and Sudbø A 2009 Phys. Rev. B 80 144507
Araújo M A N and Sacramento P D 2009 Phys. Rev. B 79 174529
[26] Chen Y C, Lu X Y, Wang M, Luo H Q and Li S L 2011 Supercond. Sci. Technol. 24 065004
[27] Zeng B, Mu G, Shen B, Cheng P, Luo H Q, Yang H, Shan L, Ren C and Wen H H 2012 Phys. Rev. B 85 224514
[28] Tortello M, Daghero D, Ummarino G A, Stepanov V A, Jiang J, Weiss J D, Hellstrom E E and Gonnelli R S 2010 Phys. Rev. Lett. 105 237002
[29] Lu X, Park W K, Yuan H Q, Chen G F, Luo G L, Wang N L, Sefat A S, McGuire M A, Jin R, Sales B C, Mandrus D, Gillett J, Sebastian S E and Greene L H 2010 Supercond. Sci. Technol. 23 054009
[30] Blonder G E, Tinkham M and Klapwijk T M 1982 Phys. Rev. B 25 4515
[31] Tanaka Y and Kashiwaya S 1995 Phys. Rev. Lett. 74 3451
Kashiwaya S, Tanaka Y, Koyanagi M and Kajimura K 1996 Phys. Rev. B 53 2667
[32] Dynes R C, Narayanamurti V and Garno J P 1978 Phys. Rev. Lett. 41 1509
[33] Chubukov A V and Eremin I 2010 Phys. Rev. B 82 060504(R)
[34] Vorontsov A B and Vekhter I 2010 Phys. Rev. Lett. 105 187004
Mazin I I, Devereaux T P, Analytis J G, Chu J H, Fisher I R, Muschler B and Hackl R 2010 Phys. Rev. B 82 180502(R)
[35] Tanatar M A, Reid J P, Shakeripour H, Luo X G, Doiron-Leyraud N, Ni N, Bud'ko S L, Canfield P C, Prozorov R and Taillefer L 2010 Phys. Rev. Lett. 104 067002
[36] Wang Z S, Wang Z Y, Luo H Q, Lu X Y, Zhu J, Li C H, Shan L, Yang H, Wen H H and Ren C 2012 Phys. Rev. B 86 060508(R) |
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