Related papers: Fermi-surface Reconstruction in the Repulsive Ferm…
The observations of quantum oscillations in overdoped cuprate superconductors were in agreement with a charge density contained in a cylindrical Fermi surface but the frequencies of lightly doped compounds were much smaller than expected.…
A system with charge conservation and lattice translation symmetry has a well-defined filling $\nu$, which is a real number representing the average charge per unit cell. We show that if $\nu$ is fractional (i.e. not an integer), this…
Electron collisions for a two dimensional Fermi liquid (FL) are shown to give a quasiparticle damping with interesting frequency and temperature variations in the BCS superconducting state. The spin susceptibility which determines the…
A quantum phase transition in strongly correlated Fermi systems beyond the topological quantum critical point is studied within the Fermi liquid approach. The transition occurs between two topologically equivalent states, each with three…
We investigate a system of one dimensional Hubbard chains of interacting fermions coupled by inter-chain hopping. Using a generalization of the Dynamical Mean Field Theory we study the deconfinement transition from a Mott insulator to a…
The notion of the electron Fermi surface is one of the characteristic concepts in the field of condensed matter physics, and it plays a crucial role in the understanding of the physical properties of doped Mott insulators. Based on the t-J…
We investigate the low energy properties of a correlated metal in the proximity of a Mott insulator within the Hubbard model in two dimensions. We introduce a new version of the Cellular Dynamical Mean Field Theory using cumulants as the…
Using the strong coupling diagram technique a self-consistent equation for the electron Green's function is derived for the repulsive Hubbard model. Terms of two lowest orders of the ratio of the bandwidth $\Delta$ to the Hubbard repulsion…
Based on the NMR measurements on Bi$_2$Sr$_{2-x}$La$_x$CuO$_{6+\delta}$ (La-Bi2201) in strong magnetic fields, we identify the non-superconducting pseudogap phase in the cuprates as a Luttinger-volume violating Fermi liquid (LvvFL). This…
The mechanism by which the Fermi surface of high-$T_c$ cuprates undergoes a dramatic change from a large hole-like barrel to small arcs or pockets on entering the pseudogap phase remains a question of fundamental importance. Here we…
We prove that the two dimensional Hubbard model at finite temperature T and half-filling is analytic in the coupling constant in a radius at least $c/(\log T)^2$. We also study the self-energy through a new two-particle irreducible…
Mean-field study of the stripe structures is conducted for a hole-doped Hubbard model. For bond-directed stripes, the Fermi surface consists of segments of an open surface and the boundaries of the hole pockets which appear in the diagonal…
We develop an analytical tool to extract bulk electronic properties of unconventional superconductors through inelastic neutron scattering (INS) spectra. Since the spin excitation spectrum in the superconducting (SC) state originates from…
We have investigated the attractive Hubbard model in the low density limit for the 2D square lattice using the ladder approximation for the vertex function in a self-consistent, conserving formulation. In the parameter region where the…
Analyzing general structure of the Green function of a strongly correlated electron system we have shown that for the regime of strong correlations Luttinger's theorem should be generalized in the following way: the volume of the Fermi…
We study the low temperature properties of the two-dimensional weakly interacting Hubbard model on $\ZZZ^2$ with renormalized chemical potential $\mu=2-\mu_0$, $\mu_0=10^{-10}$ fixed, in which case the Fermi surface is close to a perfect…
We study instabilities occurring in the electron system whose Fermi surface has flat regions on its opposite sides. Such a Fermi surface resembles Fermi surfaces of some high-$T_c$ superconductors. In the framework of the parquet…
Since the discovery of heavy-fermion superconductivity in CeCu$_{2}$Si$_{2}$, the material has attracted great interest particularly with regard to the nature of the superconducting pairing and its mechanism. Consequently, it is essential…
We study the electronic structure of the doped paramagnetic insulator by finite temperature Quantum Monte-Carlo simulations for the 2D Hubbard model. Throughout we use the moderately high temperature T=0.33t, where the spin correlation…
The search for a Fermi surface in the absence of a conventional Fermi liquid has thus far yielded very few potential candidates. Among promising materials are spin-frustrated Mott insulators near the insulator-metal transition, where theory…