相关论文: Slave fermion theory of confinement in strongly an…

We reconsider the problem of separation of spin and charge in one dimensional quantum antiferromagnets. We show that spin and charge separation in one dimensional strongly correlated systems cannot be described by the slave boson or fermion…

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 perform density-matrix renormalization group studies of a two-dimensional electron gas in a high magnetic field and with an anisotropic band mass. At half-filling in the lowest Landau level, such a system is a Fermi liquid of composite…

A novel approach, the fermion-spin transformation to implement the charge-spin separation, is developed to study the low-dimensional $t$-$J$ model. In this approach, the charge and spin degrees of freedom of the physical electron are…

Magnetic properties of Hubbard model have been studied extensively. A theoretical description of these states, however, is not straight forward within conventional mean-field approach due to the electron correlation effects. Here we provide…

An effective field theory for clean electron systems is developed in analogy to the generalized nonlinear sigma-model for disordered interacting electrons. The physical goal is to separate the soft or massless electronic degrees of freedom…

We develop the complete theory for the collective plasmon modes of an interacting electron system in the presence of explicit mass (or velocity) anisotropy in the corresponding non-interacting situation, with the effective Fermi velocity…

The mean-field theory with the use of the slave-boson functional method is generalized to take account of the spin- and orbital-ordered state in the doubly degenerate Hubbard model. Some numerical calculations are presented of the…

We investigated electron phases in the $f^2$-configuration system with the $\Gamma_1$ crystalline-electric-field (CEF) ground state in cubic symmetry. An extended three-orbital periodic Anderson model, which consists of $j=5/2$ states, is…

We show that slave particles are always confined in U(1) gauge theories of interacting electron systems. Consequently, the low-lying degrees of freedom are different from the slave particles. This is done by constructing a dual formulation…

We study the low energy properties of the one-orbital quantum double-exchange model by using the slave fermion formulation. We construct a mean-field theory which gives a simple explanation for the magnetic and thermodynamic properties of…

We consider models of heavy fermions in the strong coupling or local moment limit and include phonon degrees of freedom on the conduction electrons. Due to the large mass or low coherence temperature of the heavy fermion state, it is shown…

We consider a lattice model of itinerant electrons coupled to an array of localized classical Heisenberg spins. The nature of the ground state ordered magnetic phases that result from the indirect spin-spin coupling mediated by the…

Atomic repulsion $U_d$ on the Cu site in high T$_c$ cuprates is large but, surprisingly, some important properties are consistent with moderate couplings. The time dependent perturbation theory with slave particles is therefore formulated…

We use the SU(2) slave fermion approach to study a tetrahedral spin 1/2 chain, which is a one-dimensional generalization of the two dimensional Kitaev honeycomb model. Using the mean field theory, coupled with a gauge fixing procedure to…

Recently, we have elucidated the physics of electron fractionalization in strongly interacting electron systems using a $Z_2$ gauge theory formulation. Here we discuss the connection with the earlier U(1) gauge theory approaches based on…

We present a relativistic analysis of fermions in an external electric field by non-perturbatively solving the Dirac equation with a static gauge. Different from the magnetic field effect, the fermion wave function in an electric field…

When interacting two-dimensional electrons are placed in a large perpendicular magnetic field, to minimize their energy, they capture an even number of flux quanta and create new particles called composite fermions (CFs). These complex…

In the present paper, we study a system of doped antiferromagnet in three dimensions at finite temperatures by using the t-J model, a canonical model of strongly-correlated electrons. We employ the slave-fermion representation of electrons…

We introduce and develop a slave-spin mean-field technique for describing a generic interacting two level systems under time-dependent drivings, where an auxiliary S=1 spin is added to describe the localized character of the electrons. We…