Related papers: Pair breaking by impurities in the two-dimensional…
We report the study of spontaneous magnetization (i.e., spin-polarization) for time-reversal symmetry (TRS)-breaking superconductors with unitary pairing potentials, in the absence of external magnetic fields or Zeeman fields. Spin-singlet…
The structure of the order parameter and the excitation spectrum are investigated for isolated impurities in d-wave superconductors. Atomic scale impurities, or defects, scatter quasiparticles and lead to local suppression (pair-breaking)…
In this work we present the generalization of the model for chain formation in break-junctions, introduced by Thiess {\it et al.} [\onlinecite{Alex08}], to zigzag transition-metal chains with $s$ and $p$ impurities. We apply this extended…
Scanning tunneling microscopy (STM) by providing images of the effects of individual zinc-impurities in cuprate superconductors with unprecedented atomic-resolution offers a stringent test to models of correlated fermions for…
We suggest that the 2+1 dimensional Gross-Neveu model can give an effective field theory description of low-energy quasiparticles in high temperature superconductors. The magnetic catalysis of dynamical symmetry breaking is examined. The…
Recent scanning tunneling spectroscopy experiments have provided evidence that dopant impurities in high- Tc superconductors can strongly modify the electronic structure of the CuO2 planes nearby, and possibly influence the pairing. To…
In this paper we study the effect of non-magnetic impurities on two-band $s_{\pm}$ superconductors by deriving the corresponding Ginzburg-Landau (GL) equation. Depending on the strength of (impurity-induced) inter-band scattering we find…
We study the effect of U=0 impurities on the superconducting and thermodynamic properties of the attractive Hubbard model on a square lattice. Removal of the interaction on a critical fraction of $f_{\rm crit} \approx 0.30$ of the sites…
The superconducting state around a well isolated nonmagnetic impurity in the high-Tc superconductors is studied using the two-dimensional t-J model. The spatial dependence of the order parameter and the local density of states are obtained…
In this thesis, we theoretically examine the pairing mechanisms and the identification of the pairing symmetry of unconventional superconductors whose normal states are correlated, multiband, or topological. In the first part, we…
We consider the entanglement in a two dimensional XY model in an external magnetic field h. The model consists of a set of 7 localized spin-1/2 particles in a two dimensional triangular lattice coupled through nearest neighbor exchange…
Numerical and analytical studies of several models of correlated electrons are discussed. Based on exact diagonalization and variational Monte Carlo techniques, we have found strong indications that the two dimensional t-J model…
This study investigates the impurity effects on UTe2 within the self-consistent Born approximation using the six-orbital f-d-p model which contains two uranium and tellurium atoms in the minimum unit cell. We analyze the dependence of…
Unconventional features in superconductivity are revealed by responses to impurity scattering. We study non-magnetic impurity effects in a three-dimensional topological superconductor, focusing on an effective model (massive Dirac…
We present a theory of magnetic (Ni) and nonmagnetic (Zn) impurities substituted into planar Cu sites in the normal state of underdoped cuprates exhibiting a spin gap. Both types of impurities induce magnetic moments on neighboring Cu…
Magnetic interactions are widely believed to play a crucial role in the microscopic mechanism leading to high critical temperature superconductivity. It is therefore important to study the signatures of pairing in the magnetic excitation…
The stability of hole bound states in the t-J model including short-range Coulomb interactions is analyzed using computational techniques on ladders with up to $2 \times 30$ sites. For a nearest-neighbors (NN) hole-hole repulsion, the…
We review the role of dual pairs in mechanics and use them to derive particle-like solutions to regularized incompressible fluid systems. In our case we have a dual pair resulting from the action of diffeomorphisms on point particles…
We reported that the pair-pair correlation function of the two-dimensional t-J model does not have long-range d-wave superconducting correlations in the interesting parameter range of $J/t \leq 0.5$. The power-Lanczos method is used under…
We investigate the two-dimensional t-J model at a hole doping of x = 1/8 and J/t = 0.35 with exact diagonalization. The low-energy states are uniform (not striped). We find numerous excited states with charge density wave structures, which…