Related papers: Spin dynamics in the diluted ferromagnetic Kondo l…
The finite-T DMRG method is applied to the one-dimensional Kondo lattice model to calculate dynamic correlation functions. Dynamic spin and charge correlations, S_f(omega), S_c(omega), and N_c(omega), and quasiparticle density of states…
Scaling equations for the Kondo lattice in the paramagnetic and magnetically ordered phases are derived to two-loop order with account of spin dynamics. The results are applied to describe various mechanisms of the non-Fermi-liquid (NFL)…
Using recently developed Lanczos technique we study finite-temperature properties of the 2D Kondo lattice model at various fillings of the conduction band. At half filling the quasiparticle gap governs physical properties of the chemical…
We study the problem of a boundary magnetic impurity coupled with the solvable $t-J$ chains. Our model provides a good start point to understand the Kondo problem in a Luttinger liquid as well as in a strongly correlated host. The Kondo…
When magnetic moments are immersed into the Fermi sea of itinerant electrons, rich quantum physics emerges. This is relevant for a wide range of materials including heavy Fermion systems, high temperature superconductors like the cuprates,…
Finite-temperature properties of weakly doped antiferromagnets as modeled by the two-dimensional t-J model and relevant to underdoped cuprates are investigated by numerical studies of small model systems at low doping. Two numerical methods…
A purely fermionic representation is introduced for the ferromagnetic Kondo lattice model which allows conventional diagrammatic tools to be employed to study correlation effects. Quantum 1/S corrections to magnon excitations are…
Ferromagnetism in the Hubbard model is investigated on sc, bcc, and fcc lattices using a systematic inverse-degeneracy ($1/{\cal N}$) expansion which incorporates self-energy and vertex corrections such that spin-rotation symmetry and the…
The diluted Kondo lattice model is investigated at strong antiferromagnetic local exchange couplings J, where almost local Kondo clouds drastically restrict the motion of conduction electrons, giving rise to the possibility of quantum…
We present results of tight-binding spin-dynamics simulations of individual and pairs of substitutional Mn impurities in GaAs. Our approach is based on the mixed quantum-classical scheme for spin dynamics, with coupled equations of motions…
A formulation of the effective hybridization model is developed which describes Fermi-liquid Kondo and fractionalized Fermi-liquid (deconfinement spin-liquid-like) states with account of possible magnetic ordering. A unified consideration…
We employ the dynamical mean-field approximation to study the magnetic properties of a model relevant for the dilute magnetic semiconductors. Our model includes the spin-orbit coupling on the hole bands, the exchange interaction, and the…
The Kondo lattice model with Hund's ferromagnetic spin coupling is investigated as a microscopic model of the perovskite-type $3d$ manganese oxide (R,A)MnO$_3$ where $R$ and $A$ are rare earth element and alkaline earth element,…
The Kondo-lattice model describes a typical spin-charge coupled system in which localized spins and itinerant electrons are strongly coupled via exchange interactions and exhibits a variety of long-wavelength magnetic orders originating…
We present results of a numerical mean field treatment of interacting spins and carriers in doped diluted magnetic semiconductors, which takes into account the positional disorder present in these alloy systems. Disorder is found to enhance…
We present non-equilibrium physics in spin ice as a novel setting which combines kinematic constraints, emergent topological defects, and magnetic long range Coulomb interactions. In spin ice, magnetic frustration leads to highly degenerate…
We discuss the properties of a strongly interacting spin-charge separated one dimensional system coupled to ferromagnets and/or superconductors. Our results are valid for arbitrary temperatures with respect to the spin energy, but require…
We report results of a Monte Carlo study of doped, diluted magnetic semiconductors in the low carrier density (insulating) regime. We find that the system undergoes a transition from a paramagnet at high temperatures to a ferromagnet at low…
The evolution of low-energy spin dynamics in the iron-based superconductor LaFeAsO$_{1-x}$F$_x$ was studied over a broad doping, temperature, and magnetic field range (x = 0 - 0.15, T up to 480K, H up to 30T) by means of As nuclear magnetic…
The renormalization group formalism was applied to calculate the spin-lattice relaxation rate of a well-defined magnetic moment in the neighborhood of a spin degenerate Anderson impurity. In the Kondo regime, the spin-lattice relaxation…