Superfluid density of the ±s-wave state for the iron-based superconductors

被引:34
作者
Bang, Yunkyu [1 ,2 ]
机构
[1] Chonnam Natl Univ, Dept Phys, Kwangju 500757, South Korea
[2] Asia Pacific Ctr Theoret Phys, Pohang 790784, South Korea
关键词
LAYERED SUPERCONDUCTOR; LAO0.9F0.1-DELTA-FEAS; SCATTERING; GAPS;
D O I
10.1209/0295-5075/86/47001
中图分类号
O4 [物理学];
学科分类号
0702 ;
摘要
We study the superfluid density of the +/- s-wave state of the minimal two-band model for the Fe-based superconductors and its evolution with impurity concentration. We show that the impurity scattering of the strong-coupling limit induces the self-energy of a generic form Im Sigma(imp)(omega) approximate to i gamma + i beta omega beyond a critical impurity concentration Gamma(imp) > Gamma(crit). This form of Im Sigma(imp)(omega) causes the temperature dependence of the superfluid density [rho(s)(T) - rho(s)(0)] approximate to -gamma T(2) - beta T(3). Combined with the full gap behavior of rho(s)(T) for lower impurity concentration Gamma(imp) < Gamma(crit), the +/- s-wave state produces a continuous evolution of Delta lambda(T): exponentially -> T(3) -> T(2) with increasing impurity concentration that is consistent with the measurements of the Fe pnictide superconductors such as M-1111 (M = La, Nd, Sm, Pr) and Ba-122 with various dopings, except LaFePO which shows Delta lambda(T) proportional to T(1.2) at low temperatures by a recent experiment. Our results also demonstrate that the density of states (DOS) measured by thermodynamic properties and the DOS measured by transport properties can in general be different. Copyright (C) EPLA, 2009
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页数:6
相关论文
共 37 条
[1]   Impurity-induced states in conventional and unconventional superconductors [J].
Balatsky, A. V. ;
Vekhter, I. ;
Zhu, Jian-Xin .
REVIEWS OF MODERN PHYSICS, 2006, 78 (02) :373-433
[2]   Impurity effects on the ±s-wave state of the iron-based superconductors [J].
Bang, Yunkyu ;
Choi, Han-Yong ;
Won, Hyekyung .
PHYSICAL REVIEW B, 2009, 79 (05)
[3]   Possible pairing states of the Fe-based superconductors [J].
Bang, Yunkyu ;
Choi, Han-Yong .
PHYSICAL REVIEW B, 2008, 78 (13)
[4]   Superconductivity at 41 K and its competition with spin-density-wave instability in layered CeO1-xFxFeAs [J].
Chen, G. F. ;
Li, Z. ;
Wu, D. ;
Li, G. ;
Hu, W. Z. ;
Dong, J. ;
Zheng, P. ;
Luo, J. L. ;
Wang, N. L. .
PHYSICAL REVIEW LETTERS, 2008, 100 (24)
[5]   A BCS-like gap in the superconductor SmFeAsO0.85F0.15 [J].
Chen, T. Y. ;
Tesanovic, Z. ;
Liu, R. H. ;
Chen, X. H. ;
Chien, C. L. .
NATURE, 2008, 453 (7199) :1224-1227
[6]   Superconductivity at 43 K in SmFeAsO1-xFx [J].
Chen, X. H. ;
Wu, T. ;
Wu, G. ;
Liu, R. H. ;
Chen, H. ;
Fang, D. F. .
NATURE, 2008, 453 (7196) :761-762
[7]   Magnetism, superconductivity, and pairing symmetry in iron-based superconductors [J].
Chubukov, A. V. ;
Efremov, D. V. ;
Eremin, I. .
PHYSICAL REVIEW B, 2008, 78 (13)
[8]   Observation of Fermi-surface-dependent nodeless superconducting gaps in Ba0.6K0.4Fe2As2 [J].
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. ;
Wang, N. L. .
EPL, 2008, 83 (04)
[9]   Evidence for a Nodal-Line Superconducting State in LaFePO [J].
Fletcher, J. D. ;
Serafin, A. ;
Malone, L. ;
Analytis, J. G. ;
Chu, J. -H. ;
Erickson, A. S. ;
Fisher, I. R. ;
Carrington, A. .
PHYSICAL REVIEW LETTERS, 2009, 102 (14)
[10]   London penetration depth in single crystals of Ba(Fe1-xCox)2As2 spanning underdoped to overdoped compositions [J].
Gordon, R. T. ;
Martin, C. ;
Kim, H. ;
Ni, N. ;
Tanatar, M. A. ;
Schmalian, J. ;
Mazin, I. I. ;
Bud'ko, S. L. ;
Canfield, P. C. ;
Prozorov, R. .
PHYSICAL REVIEW B, 2009, 79 (10)