Related papers: Quantum Interference Phenomena Between Impurity St…
In materials with strong local Coulomb interactions, simple defects such as atomic substitutions strongly affect both macroscopic and local properties of the system. A nonmagnetic impurity, for instance, is seen to induce magnetism nearby.…
We review recent developments in our understanding of how impurities influence the electronic states in the bulk of superconductors. Our focus is on the quasi-localized states in the vicinity of impurity sites in conventional and…
Strong evidence is presented for the localization of low energy quasiparticle states in disordered $d$-wave superconductors. Within the framework of the Bogoliubov-de Gennes (BdG) theory applied to the extended Hubbard model with a finite…
The impurity-induced quasiparticle interference(QPI) in the parent compounds of iron-pnictide superconductors is investigated based on a phenomenological two-orbital four-band model and T-matrix method. We find the QPI is sensitive to the…
We discuss the dynamics of magnetic moments in d-wave superconductors, in particular we focus on moments induced by doping non-magnetic impurities into cuprates. The interaction of such moments with the Bogoliubov quasiparticles of the…
The effect of non-magnetic impurities on 2D s-wave superconductors is studied beyond the weak disorder regime. Within the Bogoliubov-de Gennes (BdG) framework, the local pairing amplitude develops a broad distribution with significant…
The quasiparticle scattering interference (QSI) is intimately related to the nature of the quasiparticle and of its interplay with a variety of electronic orders and superconductivity. Here starting from the microscopic octet scattering…
We study the effects of single-impurity scattering on the local density of states in the high-$T_c$ cuprates. We compare the quasiparticle interference patterns in three different ordered states: d-wave superconductor (DSC), d-density wave…
A single impurity problem is investigated for multiband s-wave superconductors with different sign order parameters (+-s-wave superconductors) suggested in Fe-pnictide superconductors. Not only intraband but also interband scattering is…
The local quasiparticle density of states around a unitary impurity with a Kondo-like magnetic moment induced at its nearest neighbors in a d-wave superconductor is studied within the slave-boson mean-field approach. The Hamiltonian is…
The absence of localization of impurity-induced low-energy quasiparticle states in a two-dimensional $d$-wave superconductor is argued for any amount of disorder in the limit of unitary scatterers. This surprising result follows from the…
In this paper we study the effect of single non-magnetic impurity in two-band s-wave superconductors where the two s-wave order parameters have relative phase $\delta\neq0$ between them. We show that in-gap bound states are always induced…
We theoretically consider the effects of having unintentional charged impurities in laterally coupled two-dimensional double (GaAs) quantum dot systems, where each dot contains one or two electrons and a single charged impurity in the…
Effect of finite density of nonmagnetic impurities on a coexisting phase of d-density wave (DDW) order and d-wave superconducting (DSC) order is studied using Bogoliubov-de Gennes (BdG) method. The spatial variation of the inhomogeneous DDW…
The impurity effects are studied for the BiS_{2}- layered superconductors based on a two orbital model with the Bogoliubov-de-Gennes technique. The superconducting critical temperature (T_{c}) as a function of the mpurity concentration is…
A numerical approach to disordered 2D superconductors described by BCS mean field theory is outlined. The energy gap and the superfluid density at zero temperature and the quasiparticle density of states are studied. The method involves…
The quasiparticle density of states (DOS), the energy gap, the superfluid density $\rho_s$, and the localization effect in the s- and d-wave superconductors with non-magnetic impurity in two dimensions (2D) are studied numerically. For…
The local density of states (LDOS) around a magnetic impurity in high-Tc superconductors is studied using the two-dimensional t-J model with a realistic band structure. The order parameters are determined in a self-consistent way within the…
We study the electronic structure near impurities in the d-density-wave (DDW) state, a possible candidate phase for the pseudo-gap region of the high-temperature superconductors. We show that the local DOS near a non-magnetic impurity in…
We study the effect of nonmagnetic impurities in the superconducting state of the t-J model. The Bogoliubov de Gennes equation is derived using a slave-boson mean-field approximation, and we solve it numerically at T=0. The d_{x^2-y^2}-wave…