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High-temperature superconductivity in iron-based materials

Abstract

The surprising discovery of superconductivity in layered iron-based materials, with transition temperatures climbing as high as 55 K, has led to thousands of publications on this subject over the past two years. Although there is general consensus on the unconventional nature of the Cooper pairing state of these systems, several central questions remain — including the role of magnetism, the nature of chemical and structural tuning, and the resultant pairing symmetry — and the search for universal properties and principles continues. Here we review the progress of research on iron-based superconducting materials, highlighting the main experimental benchmarks that have been reached so far and the important questions that remain to be conclusively answered.

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Figure 1: Experimental phase diagrams of the BaFe2As2 system.
Figure 2: Universal experimentally scalable quantities of FeAs-based superconducting materials.
Figure 3: Electronic thermal conductivity of FeAs-based systems in the superconducting state.

References

  1. 1

    Kamihara, Y., Watanabe, T., Hirano, M. & Hosono, H. Iron-based layered superconductor La[O1−xFx]FeAs(x=0.05–0.12) with Tc=26 K. J. Am. Chem. Soc. 130, 3296–3297 (2008).

    Article  Google Scholar 

  2. 2

    Takahashi, H. et al. Superconductivity at 43 K in an iron-based layered compound LaO1−xFxFeAs. Nature 453, 376–378 (2008).

    ADS  Article  Google Scholar 

  3. 3

    Ishida, K., Nakaii, Y. & Hosono, H. To what extent iron-pnictide new superconductors have been clarified: A progress report. J. Phys. Soc. Jpn 78, 062001 (2009).

    ADS  Article  Google Scholar 

  4. 4

    Johnston, D. C. The puzzle of high temperature superconductivity in layered iron pnictides and chalcogenides. Preprint at http://arxiv.org/abs/1005.4392.

  5. 5

    Luetkens, H. et al. The electronic phase diagram of the LaO1−xFxFeAs superconductor. Nature Mater. 8, 305–309 (2009).

    ADS  Article  Google Scholar 

  6. 6

    Drew, A. J. et al. Coexistence of static magnetism and superconductivity in SmFeAsO1−xFx as revealed by muon spin rotation. Nature Mater. 8, 310–314 (2009).

    ADS  Article  Google Scholar 

  7. 7

    Rotter, M., Pangerl, M., Tegel, M. & Johrendt, D. Superconductivity and crystal structures of (Ba1−xKx)Fe2As2 (x=0–1). Angew. Chem. Int. Ed. 47, 7949–7952 (2008).

    Article  Google Scholar 

  8. 8

    Ni, N. et al. Effects of Co substitution on thermodynamic and transport properties and anisotropic Hc2 in Ba(Fe1−xCox)2As2 single crystals. Phys. Rev. B 78, 214515 (2008).

    ADS  Article  Google Scholar 

  9. 9

    Jiang, S. et al. Superconductivity up to 30 K in the vicinity of the quantum critical point in BaFe2(As1−xPx)2 . J. Phys. Condens. Matter 21, 382203 (2009).

    Article  Google Scholar 

  10. 10

    Leithe-Jasper Schnelle, W., Geibel, C. & Rosner, H. Superconducting state in SrFe2−xCoxAs2 by internal doping of the iron arsenide layers. Phys. Rev. Lett. 101, 207004 (2008).

    ADS  Article  Google Scholar 

  11. 11

    Sefat, A. S. et al. Superconductivity at 22 K in Co-doped BaFe2As2 crystals. Phys. Rev. Lett. 101, 117004 (2008).

    ADS  Article  Google Scholar 

  12. 12

    Saha, S. R. et al. Superconductivity at 23 K in Pt doped BaFe2As2 single crystals. J. Phys. Condens. Matter 22, 072204 (2010).

    ADS  Article  Google Scholar 

  13. 13

    Sefat, A. S. et al. Absence of superconductivity in hole-doped BaFe2−xCrxAs2 single crystals. Phys. Rev. B 79, 224524 (2009).

    ADS  Article  Google Scholar 

  14. 14

    Liu, Y., Sun, D. L., Park, J. T. & Lin, C. T. Aliovalent ion-doped BaFe2As2: Single crystal growth and superconductivity. Physica Cdoi:10.1016/j.physc.2009.11.024 (2009).

  15. 15

    Canfield, P. C., Bud’ko, S. L., Ni, N., Yan, J. Q. & Kracher, A. Decoupling of the superconducting and magnetic/structural phase transitions in electron-doped BaFe2As2 . Phys. Rev. B 80, 060501(R) (2009).

    ADS  Article  Google Scholar 

  16. 16

    Kimber, S. A. J. et al. Similarities between structural distortions under pressure and chemical doping in superconducting BaFe2As2 . Nature Mater. 8, 471–475 (2009).

    ADS  Article  Google Scholar 

  17. 17

    Alireza, P. L. et al. Superconductivity up to 29 K in SrFe2As2 and BaFe2As2 at high pressures. J. Phys. Condens. Matter 21, 012208 (2009).

    ADS  Article  Google Scholar 

  18. 18

    Colombier, E., Bud’ko, S. L., Ni, N. & Canfield, P. C. Complete pressure-dependent phase diagrams for SrFe2As2 and BaFe2As2 . Phys. Rev. B 79, 224518 (2009).

    ADS  Article  Google Scholar 

  19. 19

    Ishikawa, F. et al. Zero-resistance superconducting phase in BaFe2As2 under high pressure. Phys. Rev. B 79, 172506 (2009).

    ADS  Article  Google Scholar 

  20. 20

    Fukazawa, H. et al. Suppression of magnetic order by pressure in BaFe2As2 . J. Phys. Soc. Jpn 77, 105004 (2008).

    ADS  Article  Google Scholar 

  21. 21

    Matsubayashi, K. et al. Intrinsic properties of AFe2As2 (A=Ba, Sr) single crystal under highly hydrostatic pressure conditions. J. Phys. Soc. Jpn 78, 073706 (2009).

    ADS  Article  Google Scholar 

  22. 22

    Yamazaki, T et al. Appearance of pressure-induced superconductivity in BaFe2As2 under hydrostatic conditions and its extremely high sensitivity to uniaxial stress. Phys. Rev. B 81, 224511 (2010).

    ADS  Article  Google Scholar 

  23. 23

    Yu, W. et al. Absence of superconductivity in single-phase CaFe2As2 under hydrostatic pressure. Phys. Rev. B 79, 020511R (2009).

    ADS  Article  Google Scholar 

  24. 24

    Yildirim, T. Strong coupling of the Fe-spin state and the As–As hybridization in iron-pnictide superconductors from first-principle calculations. Phys. Rev. Lett. 102, 037003 (2009).

    ADS  Article  Google Scholar 

  25. 25

    Saha, S. R., Butch, N. P., Kirshenbaum, K., Paglione, J. & Zavalij, P. Y. Superconducting and ferromagnetic phases induced by lattice distortions in stoichiometric SrFe2As2 single crystals. Phys. Rev. Lett. 103, 037005 (2009).

    ADS  Article  Google Scholar 

  26. 26

    Kalisky, B. et al. Enhanced superfluid density on twin boundaries in Ba(Fe1−xCox)2As2 . Phys. Rev. B 81, 184513 (2010).

    ADS  Article  Google Scholar 

  27. 27

    Singh, D. J. Electronic structure of Fe-based superconductors. Physica C 469, 418–424 (2009).

    ADS  Article  Google Scholar 

  28. 28

    Kuroki, K., Usui, H., Onari, S., Arita, R. & Aoki, H. Pnicogen height as a possible switch between high-Tc nodeless and low-Tc nodal pairings in the iron-based superconductors. Phys. Rev. B 79, 224511 (2009).

    ADS  Article  Google Scholar 

  29. 29

    Lu, D. H. et al. Electronic structure of the iron-based superconductor LaOFeP. Nature 455, 81–84 (2008).

    ADS  Article  Google Scholar 

  30. 30

    Kondo, T. et al. Momentum dependence of the superconducting gap in NdFeAsO0.9F0.1 single crystals measured by angle resolved photoemission spectroscopy. Phys. Rev. Lett. 101, 147003 (2008).

    ADS  Article  Google Scholar 

  31. 31

    Ding, H. et al. Observation of Fermi-surface-dependent nodeless superconducting gaps in Ba0.6K0.4Fe2As2 . Europhys. Lett. 83, 47001 (2008).

    ADS  Article  Google Scholar 

  32. 32

    Shishido, H. et al. Evolution of the Fermi surface of BaFe2(As1−xPx)2 on entering the superconducting dome. Phys. Rev. Lett. 104, 057008 (2010).

    ADS  Article  Google Scholar 

  33. 33

    Harrison, N. et al. Quantum oscillations in antiferromagnetic CaFe2As2 on the brink of superconductivity. J. Phys. Condens. Matter 21, 32220 (2009).

    Google Scholar 

  34. 34

    Singh, D. J. Electronic structure and doping in BaFe2As2 and LiFeAs: Density functional calculations. Phys. Rev. B 78, 094511 (2008).

    ADS  Article  Google Scholar 

  35. 35

    Utfeld, C. et al. Bulk electronic structure of optimally doped Ba(Fe1−xCox)2As2 . Phys. Rev. B 81, 064509 (2010).

    ADS  Article  Google Scholar 

  36. 36

    Sekiba, Y. et al. Electronic structure of heavily electron-doped BaFe1.7Co0.3As2 studied by angle-resolved photoemission. New J. Phys. 11, 025020 (2009).

    ADS  Article  Google Scholar 

  37. 37

    Liu, C. et al. K-doping dependence of the Fermi surface of the iron–arsenic Ba1−xKxFe2As2 superconductor using angle-resolved photoemission spectroscopy. Phys. Rev. Lett. 101, 177005 (2008).

    ADS  Article  Google Scholar 

  38. 38

    Brouet, V. et al. Nesting between hole and electron pockets in Ba(Fe1−xCox)2As2 (x=0–0.3) observed with angle-resolved photoemission. Phys. Rev. B 80, 165115 (2009).

    ADS  Article  Google Scholar 

  39. 39

    Kasahara, S. et al. Evolution from non-Fermi to Fermi liquid transport properties by isovalent doping in BaFe2(As1−xPx)2 superconductors. Phys. Rev. B 81, 184519 (2010).

    ADS  Article  Google Scholar 

  40. 40

    Rullier-Albenque, F., Colson, D., Forget, A., Thuery, P. & Poissonne, S. Hole and electron contributions to the transport properties of Ba(Fe1−xRux)2As2 single crystals. Phys. Rev. B 81, 224503 (2010).

    ADS  Article  Google Scholar 

  41. 41

    Wadati, H., Elfimov, I. & Sawatzky, G. A. Where are the extra d electrons in transition-metal substituted Fe pnictides? Preprint at http://arxiv.org/abs/1003.2663 (2010).

  42. 42

    Liu, C. et al. Evidence for a Lifshitz transition in electron-doped iron arsenic superconductors at the onset of superconductivity. Nature Phys. 6, 419–423 (2010).

    ADS  Article  Google Scholar 

  43. 43

    Liu, C. et al. Three- to two-dimensional transition of the electronic structure in CaFe2As2: A parent compound for an iron arsenic high-temperature superconductor. Phys. Rev. Lett. 102, 167004 (2009).

    ADS  Article  Google Scholar 

  44. 44

    Malaeb, W. et al. Three-dimensional electronic structure of superconducting iron pnictides observed by angle-resolved photoemission spectroscopy. J. Phys. Soc. Jpn 78, 123706 (2009).

    ADS  Article  Google Scholar 

  45. 45

    Mun, E. D., Bud’ko, S. L., Ni, N., Thaler, A. N. & Canfield, P. C. Thermoelectric power and Hall coefficient measurements on Ba(Fe1−xTx)2As2 (T=Co and Cu). Phys. Rev. B 80, 054517 (2009).

    ADS  Article  Google Scholar 

  46. 46

    Rullier-Albenque, F., Colson, D., Forget, A. & Alloul, H. Hall effect and resistivity study of the magnetic transition, carrier content, and Fermi-liquid behavior in Ba(Fe1−xCox)2As2 . Phys. Rev. Lett. 103, 057001 (2009).

    ADS  Article  Google Scholar 

  47. 47

    Lee, C-H. et al. Effect of structural parameters on superconductivity in fluorine-free LnFeAsO1−y (Ln=La, Nd). J. Phys. Soc. Jpn 77, 083704 (2008).

    ADS  Article  Google Scholar 

  48. 48

    Gooch, M. et al. Superconductivity in ternary iron pnictides: AFe2As2 (A = alkali metal) and LiFeAs. Physica Cdoi:10.1016/j.physc.2009.10.096 (2009).

  49. 49

    Mazin, I. I. & Schmalian, J. Pairing symmetry and pairing state in ferropnictides: Theoretical overview. Physica C 469, 614–623 (2009).

    ADS  Article  Google Scholar 

  50. 50

    Mazin, I. I., Singh, D. J., Johannes, M. D. & Du, M. H. Unconventional superconductivity with a sign reversal in the order parameter of LaFeAsO1−xFx . Phys. Rev. Lett. 101, 057003 (2008).

    ADS  Article  Google Scholar 

  51. 51

    Lynn, J. W. & Dai, P. Neutron studies of the iron-based family of high Tc magnetic superconductors. Physica C 469, 469–476 (2009).

    ADS  Article  Google Scholar 

  52. 52

    Lumsden, M. D. & Christianson, A. D. Magnetism in Fe-based superconductors. J. Phys. Condens. Matter 22, 203203 (2010).

    ADS  Article  Google Scholar 

  53. 53

    Yildirim, T. Origin of the 150-K anomaly in LaFeAsO: Competing antiferromagnetic interactions, frustration, and a structural phase transition. Phys. Rev. Lett. 101, 057010 (2008).

    ADS  Article  Google Scholar 

  54. 54

    Hu, W. Z. et al. Origin of the spin density wave instability in AFe2As2 (A=Ba,Sr) as revealed by optical spectroscopy. Phys. Rev. Lett. 101, 257005 (2008).

    ADS  Article  Google Scholar 

  55. 55

    Terashima, K. et al. Fermi surface nesting induced strong pairing in iron-based superconductors. Proc. Natl Acad. Sci. USA 106, 7330–7333 (2010).

    ADS  Article  Google Scholar 

  56. 56

    Coldea, A. I. et al. Fermi surface of superconducting LaFePO determined from quantum oscillations. Phys. Rev. Lett. 101, 216402 (2008).

    ADS  Article  Google Scholar 

  57. 57

    Analytis, J. G., Chu, J-H., McDonald, R. D., Riggs, S. C. & Fisher, I. R. Enhanced Fermi surface nesting in superconducting BaFe2(As1−xPx)2 revealed by de Haas–van Alphen effect. Preprint at http://arxiv.org/abs/1002.1304 (2010).

  58. 58

    Qiu, Y. et al. Spin gap and resonance at the nesting wave vector in superconducting FeSe0.4Te0.6 . Phys. Rev. Lett. 103, 067008 (2009).

    ADS  Article  Google Scholar 

  59. 59

    Yi, M. et al. Unconventional electronic reconstruction in undoped (Ba,Sr)Fe2As2 across the spin density wave transition. Phys. Rev. B 80, 174510 (2009).

    ADS  Article  Google Scholar 

  60. 60

    Eremin, I. & Chubukov, A. V. Magnetic degeneracy and hidden metallicity of the spin-density-wave state in ferropnictides. Phys. Rev. B 81, 024511 (2010).

    ADS  Article  Google Scholar 

  61. 61

    Cvetkovic, V. & Tesanovic, Z. Multiband magnetism and superconductivity in Fe-based compounds. Europhys. Lett. 85, 37002 (2009).

    ADS  Article  Google Scholar 

  62. 62

    Diallo, S. O. et al. Itinerant magnetic excitations in antiferromagnetic CaFe2As2 . Phys. Rev. Lett. 102, 187206 (2009).

    ADS  Article  Google Scholar 

  63. 63

    Zhao, J. et al. Spin waves and magnetic exchange interactions in CaFe2As2 . Nature Phys. 5, 555–560 (2009).

    ADS  Article  Google Scholar 

  64. 64

    Lv, W., Wu, J. & Phillips, P. Orbital ordering induces structural phase transition and the resistivity anomaly in iron pnictides. Phys. Rev. B 80, 224506 (2009).

    ADS  Article  Google Scholar 

  65. 65

    Kou, S-P., Li, T. & Weng, Z-Y. Coexistence of itinerant electrons and local moments in iron-based superconductors. Europhys. Lett. 88, 17010 (2009).

    ADS  Article  Google Scholar 

  66. 66

    Johannes, M. D. & Mazin, I. I. Microscopic origin of magnetism and magnetic interactions in ferropnictides. Phys. Rev. B 79, 220510(R) (2009).

    ADS  Article  Google Scholar 

  67. 67

    de la Cruz, C. et al. Magnetic order close to superconductivity in the iron-based layered LaO1−xFxFeAs systems. Nature 453, 899–902 (2008).

    ADS  Article  Google Scholar 

  68. 68

    Jesche, A., Krellner, C., de Souza, M., Lang, M. & Geibel, C. Coupling between the structural and magnetic transition in CeFeAsO. Phys. Rev. B 81, 134525 (2010).

    ADS  Article  Google Scholar 

  69. 69

    Chu, J-H., Analytis, J. G., Kucharczyk, C. & Fisher, I. R. Determination of the phase diagram of the electron-doped superconductor Ba(Fe1−xCox)2As2 . Phys. Rev. B 79, 014506 (2009).

    ADS  Article  Google Scholar 

  70. 70

    Chandra, P., Coleman, P. & Larkin, A. I. Ising transition in frustrated Heisenberg models. Phys. Rev. Lett. 64, 88–91 (1989).

    ADS  Article  Google Scholar 

  71. 71

    Urbano, R. R. et al. Distinct high-T transitions in underdoped Ba1−xKxFe2As2. Preprint at http://arxiv.org/abs/1005.3718 (2010).

  72. 72

    de la Cruz, C. et al. Lattice distortion and magnetic quantum phase transition in CeFeAs1−xPxO. Phys. Rev. Lett. 104, 017204 (2010).

    ADS  Article  Google Scholar 

  73. 73

    Chen, T. Y., Tesanovic, Z., Liu, R. H., Chen, X. H. & Chien, C. L. A BCS-like gap in the superconductor SmFeAsO0.85F0.15 . Nature 453, 1224–1227 (2008).

    ADS  Article  Google Scholar 

  74. 74

    Grafe, H-J. et al. 75As NMR studies of superconducting LaFeAsO0.9F0.1 . Phys. Rev. Lett. 101, 047003 (2008).

    ADS  Article  Google Scholar 

  75. 75

    Matano, K. et al. Spin-singlet superconductivity with multiple gaps in PrFeAsO0.89F0.11 . Europhys. Lett. 83, 57001 (2008).

    ADS  Article  Google Scholar 

  76. 76

    Ning, F. et al. 59Co and 75As NMR investigation of electron-doped high Tc superconductor BaFe1.8Co0.2As2 (Tc=22 K). J. Phys. Soc. Jpn 77, 103705 (2008).

    ADS  Article  Google Scholar 

  77. 77

    Shimizu, Y. et al. Pressure-induced antiferromagnetic fluctuations in the pnictide superconductor FeSe0.5Te0.5: 125Te NMR study. J. Phys. Soc. Jpn 78, 123709. (2009).

    ADS  Article  Google Scholar 

  78. 78

    Graser, S., Maier, T. A., Hirschfeld, P. J. & Scalapino, D. J. Near-degeneracy of several pairing channels in multiorbital models for the Fe pnictides. New J. Phys. 11, 025016 (2009).

    ADS  Article  Google Scholar 

  79. 79

    Hicks, C. W. et al. Limits on the superconducting order parameter in NdFeAsO1−xFy from scanning SQUID microscopy. J. Phys. Soc. Jpn 78, 013708 (2009).

    ADS  Article  Google Scholar 

  80. 80

    Zhang, X. et al. Observation of the Josephson effect in Pb/Ba1−xKxFe2As2 single crystal junctions. Phys. Rev. Lett. 102, 147002 (2009).

    ADS  Article  Google Scholar 

  81. 81

    Wu, J. & Phillips, P. Experimental detection of sign-reversal pairing in iron-based superconductors. Phys. Rev. B 79, 092502 (2009).

    ADS  Article  Google Scholar 

  82. 82

    Parker, D. & Mazin, I. I. Possible phase-sensitive tests of pairing symmetry in pnictide superconductors. Phys. Rev. Lett. 102, 227007 (2009).

    ADS  Article  Google Scholar 

  83. 83

    Chen, W-Q., Ma, F., Lu, Z-Y. & Zhang, F-C. π junction to probe antiphase s-wave pairing in iron pnictide superconductors. Phys. Rev. Lett. 103, 207001 (2009).

    ADS  Article  Google Scholar 

  84. 84

    Chen, C-T., Tsuei, C. C., Ketchen, M. B., Ren, Z-A. & Zhao, Z. X. Integer and half-integer flux-quantum transitions in a niobium–iron pnictide loop. Nature Phys. 6, 260–264 (2010).

    ADS  Article  Google Scholar 

  85. 85

    Hanaguri, T., Niitaka, S., Kuroki, K. & Takagi, H. Unconventional s-wave superconductivity in Fe(Se, Te). Science 328, 474–476 (2010).

    ADS  Article  Google Scholar 

  86. 86

    Fernandes, R. M. et al. Unconventional pairing in the iron arsenide superconductors. Phys. Rev. B 81, 140501 (2010).

    ADS  Article  Google Scholar 

  87. 87

    Yu, G., Li, Y., Motoyama, E. M. & Greven, M. A universal relationship between magnetic resonance and superconducting gap in unconventional superconductors. Nature Phys. 5, 873–875 (2009).

    ADS  Article  Google Scholar 

  88. 88

    Shamoto, S. et al. Inelastic neutron scattering study on the resonance mode in an optimally doped superconductor LaFeAsO0.92F0.08. Preprint at http://arxiv.org/abs/1006.4640 (2010).

  89. 89

    Christianson, A. D. et al. Unconventional superconductivity in Ba0.6K0.4Fe2As2 from inelastic neutron scattering. Nature 456, 930–932 (2008).

    ADS  Article  Google Scholar 

  90. 90

    Chi, S. et al. Inelastic neutron-scattering measurements of a three-dimensional spin resonance in the FeAs-based BaFe1.9Ni0.1As2 superconductor. Phys. Rev. Lett. 102, 107006 (2009).

    ADS  Article  Google Scholar 

  91. 91

    Lumsden, M. D. et al. Two-dimensional resonant magnetic excitation in BaFe1.84Co0.16As2 . Phys. Rev. Lett. 102, 107005 (2009).

    ADS  Article  Google Scholar 

  92. 92

    Wang, M. et al. Electron-doping evolution of the low-energy spin excitations in the iron arsenide BaFe2−xNixAs2 superconductors. Phys. Rev. B 81, 174524 (2010).

    ADS  Article  Google Scholar 

  93. 93

    Qiu, Y. et al. Spin gap and resonance at the nesting wave vector in superconducting FeSe0.4Te0.6 . Phys. Rev. Lett. 103, 067008 (2009).

    ADS  Article  Google Scholar 

  94. 94

    Wen, J. et al. Effect of magnetic field on the spin resonance in FeTe0.5Se0.5 as seen via inelastic neutron scattering FeSe0.4Te0.6 . Phys. Rev. B 81, 100513 (2010).

    ADS  Article  Google Scholar 

  95. 95

    Chubukov, A. V., Efremov, D. V. & Eremin, I. Magnetism, superconductivity, and pairing symmetry in iron-based superconductors. Phys. Rev. B 78, 134512 (2008).

    ADS  Article  Google Scholar 

  96. 96

    Maier, T. A., Graser, S., Scalapino, D. J. & Hirschfeld, P. J. Neutron scattering resonance and the iron-pnictide superconducting gap. Phys. Rev. B 79, 134520 (2009).

    ADS  Article  Google Scholar 

  97. 97

    Zhao, J. et al. Resonance as a probe of the electron superconducting gap in BaFe1.9Ni0.1As2 . Phys. Rev. B 81, 180505(R) (2010).

    ADS  Article  Google Scholar 

  98. 98

    Yashima, M. et al. Strong-coupling spin-singlet superconductivity with multiple full gaps in hole-doped Ba0.6K0.4Fe2As2 probed by 57Fe-NMR. J. Phys. Soc. Jpn 78, 103702 (2009).

    ADS  Article  Google Scholar 

  99. 99

    Parker, D., Dolgov, O. V., Korshunov, M. M., Golubov, A. A. & Mazin, I. I. Extended s± scenario for the nuclear spin-lattice relaxation rate in superconducting pnictides. Phys. Rev. B 78, 134524 (2008).

    ADS  Article  Google Scholar 

  100. 100

    Mishra, V., Vorontsov, A., Hirschfeld, P. J. & Vekhter, I. Theory of thermal conductivity in extended-s state superconductors: Application to ferropnictides. Phys. Rev. B 80, 224525 (2009).

    ADS  Article  Google Scholar 

  101. 101

    Luo, X. G. et al. Quasiparticle heat transport in single-crystalline Ba1−xKxFe2As2: Evidence for a k-dependent superconducting gap without nodes. Phys. Rev. B 80, 140503(R) (2009).

    ADS  Article  Google Scholar 

  102. 102

    Tanatar, M. A. et al. Doping dependence of heat transport in the iron–arsenide superconductor Ba(Fe1−xCox)2As2: From isotropic to a strongly k-dependent gap structure. Phys. Rev. Lett. 104, 067002 (2010).

    ADS  Article  Google Scholar 

  103. 103

    Dong, J. K. et al. Thermal conductivity of overdoped BaFe1.73Co0.27As2 single crystal: Evidence for nodeless multiple superconducting gaps and interband interactions. Phys. Rev. B 81, 094520 (2010).

    ADS  Article  Google Scholar 

  104. 104

    Ding, L. et al. Nodeless superconducting gap in electron-doped BaFe1.9Ni0.1As2 probed by quasiparticle heat transport. New J. Phys. 11, 093018 (2009).

    ADS  Article  Google Scholar 

  105. 105

    Dong, J. K. et al. Quantum criticality and nodal superconductivity in the FeAs-based superconductor KFe2As2 . Phys. Rev. Lett. 104, 087005 (2010).

    ADS  Article  Google Scholar 

  106. 106

    Hashimoto, K. et al. Line nodes in the energy gap of high-temperature superconducting BaFe2(As1−xPx)2 from penetration depth and thermal conductivity measurements. Phys. Rev. B 81, 220501(R) (2010).

    ADS  Article  Google Scholar 

  107. 107

    Mishra, V. et al. Lifting of nodes by disorder in extended-s-state superconductors: Application to ferropnictides. Phys. Rev. B 79, 094512 (2009).

    ADS  Article  Google Scholar 

  108. 108

    Reid, J-Ph. et al. Nodes in the gap structure of the iron–arsenide superconductor Ba(Fe1−xCox)2As2 from c-axis heat transport measurements. Phys. Rev. B 82, 064501 (2010).

    ADS  Article  Google Scholar 

  109. 109

    Laad, M. S. & Craco, L. Theory of multiband superconductivity in iron pnictides. Phys. Rev. Lett. 103, 017002 (2009).

    ADS  Article  Google Scholar 

  110. 110

    Zeng, B. et al. Anisotropic structure of the order parameter in FeSe0.4Te0.6 revealed by angle resolved specific heat. Preprint at http://arxiv.org/abs/1007.3597 (2010).

  111. 111

    Hashimoto, K. et al. Microwave surface-impedance measurements of the magnetic penetration depth in single crystal Ba1−xKxFe2As2 superconductors: Evidence for a disorder-dependent superfluid density. Phys. Rev. Lett. 102, 207001 (2009).

    ADS  Article  Google Scholar 

  112. 112

    Kim, H. et al. London penetration depth in Ba(Fe1−xTx)2As2 (T=Co, Ni) superconductors irradiated with heavy ions. Preprint at http://arxiv.org/abs/1003.2959 (2010).

  113. 113

    Martin, C. et al. Nonexponential London penetration depth of FeAs-based superconducting RFeAsO0.9F0.1 (R=La, Nd) single crystals. Phys. Rev. Lett. 102, 247002 (2009).

    ADS  Article  Google Scholar 

  114. 114

    Luan, L. et al. Local measurement of the penetration depth in the pnictide superconductor Ba(Fe0.95Co0.05)2As2 . Phys. Rev. B 81, 100501 (2010).

    ADS  Article  Google Scholar 

  115. 115

    Gofryk, K. et al. Doping-dependent specific heat study of the superconducting gap in Ba(Fe1−xCox)2As2 . Phys. Rev. B 81, 184518 (2010).

    ADS  Article  Google Scholar 

  116. 116

    Kim, J. S. et al. Specific heat vs field in the 30 K superconductor BaFe2(As0.7P0.3)2 . Phys. Rev. B 81, 214507 (2010).

    ADS  Article  Google Scholar 

  117. 117

    Hardy, F. et al. Doping evolution of superconducting gaps and electronic densities of states in Ba(Fe1−xCox)2As2 iron pnictides. Preprint at http://arxiv.org/abs/1007.2218 (2010).

  118. 118

    Popovich, P. et al. Specific heat of Ba0.68K0.32Fe2As2: Evidence for multiband strong-coupling superconductivity. Phys. Rev. Lett. 105, 027003 (2010).

    ADS  Article  Google Scholar 

  119. 119

    Mu, G. et al. Low temperature specific heat of the hole-doped Ba0.6K0.4Fe2As2 single crystals. Phys. Rev. B 79, 174501 (2009).

    ADS  Article  Google Scholar 

  120. 120

    Welp, U. et al. Specific heat and phase diagrams of single crystal iron pnictide superconductors. Physica C 469, 575–581 (2009).

    ADS  Article  Google Scholar 

  121. 121

    Bang, Y. Volovik effect in the ±s-wave state for the iron-based superconductors. Phys. Rev. Lett. 104, 217001 (2010).

    ADS  Article  Google Scholar 

  122. 122

    Bud’ko, S. L., Ni, N. & Canfield, P. C. Jump in specific heat at the superconducting transition temperature in Ba(Fe1−xCox)2As2 and Ba(Fe1−xNix)2As2 single crystals. Phys. Rev. B 79, 220516 (2009).

    ADS  Article  Google Scholar 

  123. 123

    Kant, C. et al. Magnetic and superconducting transitions in Ba1−xKxFe2As2 studied by specific heat. Phys. Rev. B 81, 014529 (2010).

    ADS  Article  Google Scholar 

  124. 124

    Hardy, F. et al. Calorimetric evidence of multiband superconductivity in Ba(Fe0.925Co0.075)2As2 single crystals. Phys. Rev. B 81, 060501(R) (2010).

    ADS  Article  Google Scholar 

  125. 125

    Ni, N. et al. Phase diagrams of Ba(Fe1−xMx)2As2 single crystals (M=Rh and Pd). Phys. Rev. B 80, 024511 (2009).

    ADS  Article  Google Scholar 

  126. 126

    Hu, R., Bozin, E. S., Warren, J. B. & Petrovic, C. Superconductivity, magnetism, and stoichiometry of single crystals of Fe1+y(Te1−xSx)z . Phys. Rev. B 80, 214514 (2009).

    ADS  Article  Google Scholar 

  127. 127

    Analytis, J. G. et al. Bulk superconductivity and disorder in single crystals of LaFePO. Preprint at http://arxiv.org/abs/0810.5368 (2008).

  128. 128

    Baumbach, R. E. et al. Superconductivity in LnFePO (Ln=La, Pr and Nd) single crystals. New J. Phys. 11, 025018 (2009).

    ADS  Article  Google Scholar 

  129. 129

    Braithwaite, D., Lapertot, G., Knafo, W. & Sheikin, I. Evidence for anisotropic vortex dynamics and Pauli limitation in the upper critical field of FeSe1−xTex . J. Phys. Soc. Jpn 79, 053703 (2010).

    ADS  Article  Google Scholar 

  130. 130

    Sato, M. et al. Studies on effects of impurity doping and NMR measurements of La 1111 and/or Nd 1111 Fe-pnictide superconductors. J. Phys. Soc. Jpn 79, 014710 (2010).

    ADS  Article  Google Scholar 

  131. 131

    Zaanen, J. Specific-heat jump at the superconducting transition and the quantum critical nature of the normal state of pnictide superconductors. Phys. Rev. B 80, 212502 (2009).

    ADS  Article  Google Scholar 

  132. 132

    Kogan, V. G. Pair breaking in iron pnictides. Phys. Rev. B 80, 214532 (2009).

    ADS  Article  Google Scholar 

  133. 133

    Tarantini, C. et al. Suppression of the critical temperature of superconducting NdFeAs(OF) single crystals by Kondo-like defect sites induced by α-particle irradiation. Phys. Rev. Lett. 104, 087002 (2010).

    ADS  Article  Google Scholar 

  134. 134

    Muschler, B. et al. Band- and momentum-dependent electron dynamics in superconducting Ba(Fe1−xCox)2As2 as seen via electronic Raman scattering. Phys. Rev. B 80, 180510 (2009).

    ADS  Article  Google Scholar 

  135. 135

    Williams, T. J. et al. Muon spin rotation measurement of the magnetic field penetration depth in Ba(Fe0.926Co0.074)2As2: Evidence for multiple superconducting gaps. Phys. Rev. B 80, 094501 (2009).

    ADS  Article  Google Scholar 

  136. 136

    Yin, Y. et al. Scanning tunneling spectroscopy and vortex imaging in the iron pnictide superconductor BaFe1.8Co0.2As2 . Phys. Rev. Lett. 102, 097002 (2009).

    ADS  Article  Google Scholar 

  137. 137

    Boeri, L., Calandra, M., Mazin, I. I., Dolgov, O.V. & Mauri, F. Effects of magnetism and doping on the electron–phonon coupling in BaFe2As2 . Phys. Rev. B 82, 020506(R) (2010).

    ADS  Article  Google Scholar 

  138. 138

    Liu, R. H. et al. A large iron isotope effect in SmFeAsO1−xFx and Ba1−xKxFe2As2 . Nature 459, 64–67 (2009).

    ADS  Article  Google Scholar 

  139. 139

    Shirage, P. M. et al. Absence of an appreciable iron isotope effect on the transition temperature of the optimally doped SmFeAsO1−y superconductor. Phys. Rev. Lett. 105, 037004 (2010).

    ADS  Article  Google Scholar 

  140. 140

    Qazilbash, M. M. et al. Electronic correlations in the iron pnictides. Nature Phys. 5, 647–650 (2009).

    ADS  Google Scholar 

  141. 141

    Yang, W. L. et al. Evidence for weak electronic correlations in iron pnictides. Phys. Rev. B 80, 014508 (2009).

    ADS  Article  Google Scholar 

  142. 142

    Yin, Z. P., Haule, K. & Kotliar, G. Magnetism and charge dynamics in iron pnictides. Preprint at http://arxiv.org/abs/1007.2867 (2010).

  143. 143

    Wang, X. F. et al. Anisotropy in the electrical resistivity and susceptibility of superconducting BaFe2As2 single crystals. Phys. Rev. Lett. 102, 117005 (2009).

    ADS  Article  Google Scholar 

  144. 144

    Bonville, P., Rullier-Albenque, F., Colson, D. & Forget, A. Incommensurate spin density wave in Co-doped BaFe2As2 . Europhys. Lett. 89, 67008 (2010).

    ADS  Article  Google Scholar 

  145. 145

    Diallo, S. O. et al. Paramagnetic spin correlations in CaFe2As2 single crystals. Phys. Rev. B 81, 214407 (2010).

    ADS  Article  Google Scholar 

  146. 146

    Ning, F. L. et al. Contrasting spin dynamics between underdoped and overdoped Ba(Fe1−xCox)2As2 . Phys. Rev. Lett. 104, 037001 (2010).

    ADS  Article  Google Scholar 

  147. 147

    Dai, J., Si, Q., Zhu, J-X. & Abrahams, E. Iron pnictides as a new setting for quantum criticality. Proc. Natl Acad. Sci. 106, 4118–4121 (2010).

    ADS  Article  Google Scholar 

  148. 148

    Nakai, Y. et al. Unconventional superconductivity and antiferromagnetic quantum critical behaviour in the isovalent-doped BaFe2(As1−xPx)2. Preprint at http://arxiv.org/abs/1005.2853 (2010).

  149. 149

    Goko, T. et al. Superconducting state coexisting with a phase-separated static magnetic order in (Ba,K)Fe2As2, (Sr,Na)Fe2As2, and CaFe2As2 . Phys. Rev. B 80, 024508 (2009).

    ADS  Article  Google Scholar 

  150. 150

    Laplace, Y., Bobroff, J., Rullier-Albenque, F., Colson, D. & Forget, A. Atomic coexistence of superconductivity and incommensurate magnetic order in the pnictide Ba(Fe1−xCox)2As2 . Phys. Rev. B 80, 140501 (2009).

    ADS  Article  Google Scholar 

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Acknowledgements

The authors would like to thank P. J. Hirschfeld, J. W. Lynn, I. I. Mazin, D. J. Scalapino and L. Taillefer for discussions and comments. This research was supported by AFOSR-MURI under FA9550-09-1-0603.

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Paglione, J., Greene, R. High-temperature superconductivity in iron-based materials. Nature Phys 6, 645–658 (2010). https://doi.org/10.1038/nphys1759

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