Related papers: Magnetic impurities in a charge-ordered background
We present a determinant quantum Monte Carlo study of the competition between instantaneous on-site Coulomb repulsion and retarded phonon-mediated attraction between electrons, as described by the two dimensional Hubbard-Holstein model. At…
Several material families show competition between superconductivity and other orders. When such competition is driven by doping, it invariably involves spatial inhomogeneities which can seed competing orders. We study impurity-induced…
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 consider a magnetic impurity which interacts by hybridization with a system of strongly correlated conduction electrons. The latter are described by a Hubbard Hamiltonian. By means of a canconical transformation the charge degrees of…
The coexistent state of the spin density wave (SDW) and the charge density wave (CDW) in the one-dimensional quarter-filled system and with the Coulomb interaction up to the next-nearest sites under magnetic fields is studied. It is found…
We consider a magnetic impurity which interacts by hybridization with a system of weakly correlated electrons and determine the energy of the ground state by means of an 1/N_f expansion. The correlations among the conduction electrons are…
Using numerical techniques we study the zero temperature properties of a substitutional magnetic impurity in a one-dimensional correlated system described by the Hubbard model with repulsive interaction $U$. We find that, while the static…
Magnetic impurities in strongly correlated electronic systems serve as sensitive probes to a wide range of many-body quantum phenomena. Broken symmetries in such a system can lead to inequivalent lattice sites, and magnetic impurities may…
We study a magnetic impurity embedded in a correlated electron system using the density-matrix renormalization group method. The correlated electron system is described by the one-dimensional Hubbard model. At half filling, we confirm that…
We study the influence of disorder and randomly distributed impurities on the properties of correlated antiferromagnets. To this end the Hubbard model with (i) random potentials, (ii) random hopping elements, and (iii) randomly distributed…
The influence of dilution with non--magnetic impurities on the order in the ground state of the $S=1/2$ Heisenberg antiferromagnet is investigated by Quantum Monte Carlo simulations. Data of the spin correlation functions and thermodynamic…
We study the physics of dilute magnetic impurities in a two-dimensional altermagnetic metal. For the single impurity case, although the spin degeneracy is broken in an altermagnetic metal, we show that the antiferromagnetic Kondo coupling…
The interplay between electron-electron correlations and disorder has been a central theme of condensed matter physics over the last several decades, with particular interest in the possibility that interactions might cause delocalization…
We study effects of classical magnetic impurities on the Anderson metal-insulator transition numerically. We find that a small concentration of Heisenberg impurities enhances the critical disorder amplitude $W_{\rm c}$ with increasing…
We study theoretically the effects of strong pinning centers on a charge density wave in the limit that the charge density wave coherence length is shorter than the average inter-impurity distance. An analysis based on a Ginzburg-Landau…
The charged and magnetic states of isolated impurities dissolved in amorphous metallic alloy are investigated. The Hamiltonian of the system under study is the generalization of Anderson impurity model. Namely, the processes of elastic and…
The Coulomb impurity problem of graphene, in the absence of a magnetic field, displays discrete scale invariance. Applying a magnetic field introduces a new magnetic length scale $\ell$ and breaks discrete scale invariance. Moreover, a…
Exact results for the thermodynamic properties of ensembles of magnetic impurities with randomly distributed host-impurity couplings in the quantum antiferromagnetic Heisenberg model are presented. Exact calculations are done for arbitrary…
We study striped morphologies induced by magnetic impurities in d-wave superconductors (DSCs) near optimal doping by self-consistently solving the Bogoliubov-de Gennes equations based on the $t-t^{\prime }-U-V$ model. For the single…
We investigate the role of electron-electron and electron-phonon interactions in strongly correlated systems by performing unbiased quantum Monte Carlo simulations in the square lattice Hubbard-Holstein model at half-filling. We study the…