Related papers: Slave-spin approach to the strongly correlated sys…
We study how to incorporate Mott physics in the BCS-type superconductor, motivated from the fact that high $T_c$ superconductivity results from a Mott insulator via hole doping. The U(1) slave-rotor representation was proposed to take local…
With the Becchi-Rouet-Stora-Tyutin (BRST) quantization of gauge theory, we solve the long-standing difficult problem of the local constraint conditions, i.e., the single occupation of a slave particle per site, in the slave particle theory.…
A simple slave-boson representation combined with the Hartree-Fock approximation for the Hund's rule coupling is introduced for a doubly degenerate narrow band, which bears a direct relation to that introduced previously in the…
The slave-boson mean-field method is used to study the two-dimensional Hubbard model. A magnetic phase diagram allowing for paramagnetism, weak- and strong ferromagnetism and antiferromagnetism, including all continuous and first-order…
We introduce the generalization of the Slave-Spin Mean-Field method to broken-symmetry phases. Through a variational approach we derive the single-particle energy shift in the mean-field equations which generates the appropriate…
We construct a new $U(1)$ slave spin representation for the single band Hubbard model in the large-$U$ limit. The mean-field theory in this representation is more amenable to describe both the spin-charge-separation physics of the Mott…
A two-dimensional Falicov-Kimball model, equivalent to the Hubbard model in an unconstrained slave-spin representation, is studied by quantum Monte Carlo simulations. The focus is on a fractionalized metallic phase that is characterized in…
A new formulation for the study of interacting bosons on a lattice is introduced. This approach is used to give analytical expressions for the Mott insulating lobes in the phase diagram and to calculate the density-density correlation…
The spectrum of the strongly correlated systems usually shows resonant peaks at finite energy, with examples in the 115 Ce family which are reproduced by the dynamical mean-field theory. A similar structure has been seen recently in the…
We analyze the $t$-$J$ model using the ${\rm CP}^1$ representation for the slave operators (holons and spinons) which is particularly suited to study the phenomenon of the spin-charge separation in strongly correlated electron systems. In…
Motivated by the debate of spin-density-wave (SDW) versus local-moment (LM) picture in the iron-based superconducting (FeSC) materials, we consider a two-band orbital-symmetric Hubbard model in which there is robust Fermi surface nesting at…
We review a representation of Hubbard-like models that is based on auxiliary pseudospin variables. These pseudospins refer to the local charge modulo two in the original model and display a local Z_2 gauge freedom. We discuss the associated…
We present a systematic derivation of effective lattice spin Hamiltonians derived from a rotationally invariant multi-orbital Hubbard model including a term ensuring Hund's rule coupling. The Hamiltonians are derived down-folding the…
We introduce a real-space slave rotor theory of the physics of topological Mott insulators, using the Kane-Mele-Hubbard model as an example, and use it to show that a topological gap in the Green function zeros corresponds to a gap in the…
The uniform static spin susceptibility in the paraphase of the one-band Hubbard model is calculated within a theory of magnetic short--range order (SRO) which extends the four-field slave-boson functional-integral approach by the trans-…
We derive an exact operatorial reformulation of the rotational invariant slave boson method and we apply it to describe the orbital differentiation in strongly correlated electron systems starting from first principles. The approach enables…
We determine the localization threshold in a partially filled and orbitally degenerate model of correlated electrons. Particular emphasis is put on a non-integer band filling, when the system decomposes into the localized and the itinerant…
We use the Kotliar-Ruckenstein slave-boson formalism to study the temperature dependence of paramagnetic phases of the one-band Hubbard model for a variety of band structures. We calculate the Fermi liquid quasiparticle spectral weight $Z$…
We determine the free energy of strongly correlated electron systems in the example of the Hubbard model by calculating the contribution of spin and charge fluctuations to the Gutzwiller approximation mean field result. We employ the slave…
In the context of the U(1) slave boson theory we derive a critical field theory near the quantum critical point of the Kondo lattice model in two spatial dimensions. First we argue that strong gauge fluctuations in the U(1) slave boson…