Related papers: Superconductor--insulator transition in d-wave sup…
We point out that in two-dimensional systems like high-$T_c$ superconductors, an isotropic s-wave electron-phonon interaction in the momentum decoupling regime leads to either s or d-wave superconductivity depending on the conventional…
There are many systems in which two order parameters compete with each other. Of particular interest are systems in which these order parameters are both unconventional. In this contribution, we examine the representative example of a…
While insensitive to weak non magnetic disorder, an s-wave superconductor can be driven insulating by strong disorder. Using a scheme that captures the correct ground state, and fully retains thermal amplitude and phase fluctuations, we…
Recently developed numerical methods have enabled the explicit construction of the superconducting state of the Hubbard model of strongly correlated electrons in parameter regimes where the model also exhibits a pseudogap and a Mott…
We study an electronic model of a 2D superconductor with onsite randomness using Quantum Monte Carlo simulations. The superfluid density is used to track the destruction of superconductivity in the ground state with increasing disorder. The…
We develop a theory of a pseudogap state appearing near the superconductor-insulator transition in strongly disordered metals with attractive interaction. We show that such an interaction combined with the fractal nature of the single…
In contrast to conventional s-wave superconductivity, unconventional (e.g. p or d-wave) superconductivity is strongly suppressed even by relatively weak disorder. Upon approaching the superconductor-metal transition, the order parameter…
We argue that the $d_{x^2-y^2}$-wave superconductor is marginally stable in the presence of external perturbations. Subjected to the external perturbations by magnetic impurities, it develops a secondary component of the gap, complex…
In the weak coupling BCS-approximation normal impurities do not influence superconducting T_{c} in significant manner in case of isotropic s-wave pairing. However, in case of d-wave pairing these are strongly pair-breaking. This fact is in…
An intricate interplay between superconductivity, pseudogap and Mott transition, either bandwidth driven or doping driven, occurs in materials. Layered organic conductors and cuprates offer two prime examples. We provide a unified…
We examine the effects of a phenomenological pseudogap on the T=0 K phase diagram of a high temperature superconductor within a self-consistent model which exhibits a d-wave pairing symmetry. At the mean-field level the presence of a…
We study the superconducting phase with two component order parameter scenario, such as, $d_{x^2-y^2} + e^{i\theta}s_{\alpha}$, where $\alpha = xy, x^2+y^2$. We show, that in absence of orthorhombocity, the usual $d_{x^2-y^2}$ does not mix…
We discuss the instability of uniform superconducting states that contain the pairing correlations belonging to the odd-frequency symmetry class. The instability originates from the paramagnetic response of odd-frequency Cooper pairs and is…
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 derive the polarizability of an electron system in (i) the superconducting phase, with d-wave symmetry, (ii) the pseudogap regime, within the precursor pairing scenario, and (iii) the d-density-wave (dDW) state, characterized by a d-wave…
We show that an induced $s$-wave harmonic in the superconducting gap of an orthorhombic $d_{x^2-y^2}$ superconductor strongly affects the excitation spectrum near a twinning plane. In particular, it yields bound states of zero energy with…
We study the properties of an anisotropically paired superconductor in the presence of a specularly reflecting surface. The bulk stable phase of the superconducting order parameter is taken to have $d_{x^2-y^2}$ symmetry. Contributions by…
In this article we study superconductor-insulator transitions within the general framework of an attractive Hubbard model. This is a well-defined model of s-wave superconductivity which permits different tuning parameters (disorder and…
In view of the current interest in d_{x^{2}-y^{2}}+id_{xy} superconductors some of their thermodynamic properties have been studied to obtain relevant information for experimental verification. The temperature dependence of the specific…
Superconductivity in the cuprates is characterized by spatial inhomogeneity and an anisotropic electronic gap of d-wave symmetry. The aim of this work is to understand how this anisotropy affects the non-equilibrium electronic response of…