TY - JOUR
T1 - Impurity-induced subgap bound states in alkali-doped iron chalcogenide superconductors
AU - Mukherjee, Shantanu
AU - Gastiasoro, Maria N.
AU - Andersen, Brian M.
PY - 2013/10/11
Y1 - 2013/10/11
N2 - Measurements of the local density of states near impurities can be useful for identifying the superconducting gap structure in alkali-doped iron chalcogenide superconductors KxFe2-ySe2. Here, we study the effects of nonmagnetic and magnetic impurities within a nearest-neighbor d-wave and next-nearest-neighbor s-wave superconducting state. For both repulsive and attractive nonmagnetic impurities, it is shown that subgap bound states exist only for d-wave superconductors with the positions of these bound states depending rather sensitively on the electron doping level. Further, for such disorder, Coulomb interactions can lead to local impurity-induced magnetism in the case of d-wave superconductivity. For magnetic impurities, both s-wave and d-wave superconducting states support subgap bound states. The above results can be explained by a simple analytic model that provides a semiquantitative understanding of the variation of the impurity bound states energies as a function of impurity potential and chemical doping level.
AB - Measurements of the local density of states near impurities can be useful for identifying the superconducting gap structure in alkali-doped iron chalcogenide superconductors KxFe2-ySe2. Here, we study the effects of nonmagnetic and magnetic impurities within a nearest-neighbor d-wave and next-nearest-neighbor s-wave superconducting state. For both repulsive and attractive nonmagnetic impurities, it is shown that subgap bound states exist only for d-wave superconductors with the positions of these bound states depending rather sensitively on the electron doping level. Further, for such disorder, Coulomb interactions can lead to local impurity-induced magnetism in the case of d-wave superconductivity. For magnetic impurities, both s-wave and d-wave superconducting states support subgap bound states. The above results can be explained by a simple analytic model that provides a semiquantitative understanding of the variation of the impurity bound states energies as a function of impurity potential and chemical doping level.
UR - http://www.scopus.com/inward/record.url?scp=84885702914&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84885702914&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.88.134508
DO - 10.1103/PhysRevB.88.134508
M3 - Article
AN - SCOPUS:84885702914
SN - 1098-0121
VL - 88
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 13
M1 - 134508
ER -