Disorder effects in multiorbital $s_{\pm}$-wave superconductors: Implications for Zn-doped BaFe$_2$As$_2$ compounds
ORAL
Abstract
Recent experiments on Zn-doped 122-type iron pnictides, Ba(Fe$_{1-x-y}$Co$_y$Zn$_x$)$_2$As$_2$, are challenging our understanding of electron doping the 122s and the interplay between doping and impurity scattering. To resolve this enigma, we investigate the disorder effects of nonmagnetic Zn impurities on various properties of the system in the $s_{\pm}$-wave pairing state. The BdG is solved based on a minimal two-orbital model with an extended range of impurity concentrations. With increasing Zn concentration the density of states shows a gradual filling of the gap, revealing pair breaking effect. Both the averaged superconducting order parameter and superfluid density are dramatically suppressed towards the dirty limit, indicating the violation of the Anderson theorem and breakdown of the AG theory for impurity-averaged Green's functions. The superconductivity is fully suppressed close to the critical impurity concentration of $n_{\mathrm{imp}}\approx 10\%$, in agreement with recent experiments.
*NSF No.11274084, Z6110033, PHYS-1066293, 973 No. 2010CB923000, RAWF No. E-1146, LANL LDRD, CIN, U.S. DOE
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Authors
Hua Chen
ZIMP, Zhejiang University, 310027, China
Yuan-Yen Tai
Department of Physics and Texas Center for Superconductivity, University of Houston
Univ of Houston Dept of Physics
Department of Physics and Texas Center for Superconductivity, University of Houston, Houston, Texas 77204, USA
C.S. Ting
Univ of Houston Dept of Physics
Department of Physics and Texas Center for Superconductivity, University of Houston, Houston, Texas 77204, USA
Matthias J. Graf
Los Alamos National Laboratory
Los Alamos National Lab
Theoretical Division and Center for Nonlinear Studies, LANL, Los Alamos, New Mexico 87545, USA
Jianhui Dai
Department of Physics, Hangzhou Normal University, 310036, China
Jian-Xin Zhu
Los Alamos National Laboratory
Theoretical Division and Center for Integrated Nanotechnologies, Los Alamos National Laboratory
Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
Theoretical Division and Center for Integrated Technologies, Los Alamos National Laboratory
Center for Integrated Nanotechnologies, Los Alamos National Laboratory
Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545
Los Alamos National Lab
Theoretical Division and Center for Nonlinear Studies, LANL, Los Alamos, New Mexico 87545, USA
