Modulation of pairing symmetry with bond disorder in unconventional superconductors

Abstract

We study a two-orbital $t$-$J_1$-$J_2$ model, originally developed to describe iron-based superconductors at low energies, in the presence of bond disorder (via next-nearest-neighbor $J_2$-bond dilution). By using the Bogoliubov--de Gennes approach, we self-consistently calculate the local pairing amplitudes and the corresponding density of states, which demonstrate a change of dominant pairing symmetry from $s_{\pm }$ wave to $d$ wave when increasing disorder strength as long as $J_1\lesssim J_2$. Moreover, the combined pairing interaction and strong bond disorder lead to the formation of $s_{\pm }$ wave "islands" with length scale of the superconducting coherence length embedded in a $d$ wave "sea." This picture is further complemented by the disorder-averaged pair-pair correlation functions, distinct from the case with potential disorder, where the "sea" is insulating. Due to this inevitable formation of spatial inhomogeneity, the superconducting $T_c$ determined by the superfluid density ${\rho }_s(T)$ obviously deviates from the value predicted by the conventional Abrikosov-Gorkov theory, where the pairing amplitudes are viewed as uniformly suppressed as the disorder increases.

10 pages, 12 figures

References in corpus (19)

• Theory of Intertwined Orders in High Temperature Superconductors
• Strong Correlations and Magnetic Frustration in the High Tc Iron Pnictides
• Magnetism and its microscopic origin in iron-based high-temperature superconductors
• Nematic and meta-nematic transitions in the iron pnictides
• Pairing Symmetry in a Two-Orbital Exchange Coupling Model of Oxypnictides
• Nature of the superconductor-insulator transition in disordered superconductors
• Superconductivity up to 30 K in the vicinity of quantum critical point in BaFe${}_2$(As${}_{1-x}$P${}_x$)${}_2$
• Iron based high transition temperature superconductors
• Evidence for nodal superconductivity in LaFePO
• Fermi surface of superconducting LaFePO determined by quantum oscillations
• Microwave Surface-Impedance Measurements of the Magnetic Penetration Depth in Single Crystal Ba1-xKxFe2As2 Superconductors: Evidence for a Disorder-Dependent Superfluid Density
• Unconventional London penetration depth in Ba(Fe0.93Co0.07)2As2 single crystals
• Antiferromagnetically Driven Electronic Correlation in Iron Pnictides and Cuprates
• Theory of quantum metal to superconductor transitions in highly conducting systems
• Hole and Electron Contributions to the Transport Properties of Ba(Fe_(1-x)Ru_x)_2As_2 Single Crystals
• Doping evolution of the absolute value of the London penetration depth and superfluid density in single crystals of Ba(Fe${}_{1-x}$Co${}_x$)${}_2$As${}_2$
• d-wave to s-wave to normal metal transitions in disordered superconductors
• Possible pi-phase shift at interface of two pnictides with antiphase s-wave pairing
• Isotropic Quenched Disorder Triggers a Robust Nematic State in Electron-Doped Pnictides

Cited by in corpus (1)

• Spin Glass in the Bond-Diluted J1-J2 Ising Model on the Square Lattice