Related papers: Ferromagnetically coupled dimers on the distorted …
The phase diagram of Sr3Ru2O7 contains a metamagnetic transition that bifurcates to enclose an anomalous phase with intriguing properties - a large resistivity with anisotropy that breaks the crystal-lattice symmetry. We propose that this…
We employ the cluster slave-spin method to investigate systematically the ground state properties of the Hubbard model on a square lattice with doping $\delta$ and coupling strength $U$ being its parameters. In addition to a crossover…
We present specific-heat and neutron-scattering results for the \emph{S}=1/2 quantum antiferromagnet (dimethylammonium)(3,5-dimethylpyridinium)CuBr$_4$. The material orders magnetically at \emph{T}$_N$=1.99(2)\,K, and magnetic excitations…
We study magnetic ordering of an extended Kondo-lattice model including an additional on-site Coulomb interaction between the itinerant states. The model is solved in the dynamical mean-field theory using Wilson's numerical renormalization…
Using the Density Matrix Renormalization Group and two-leg ladders, we investigate an electronic two-orbital Hubbard model including plaquette diagonal hopping amplitudes. Our goal is to search for regimes where charges added to the undoped…
We present the exact dimer ground state of a quantum antiferromagnet on the maple-leaf lattice. A coupling anisotropy for one of the three inequivalent nearest-neighbor bonds is sufficient to stabilize the dimer state. Together with the…
The $S=1/2$ Heisenberg antiferromagnet on the orthogonal-dimer lattice (Shastry-Sutherland model) is studied by the Lanczos diagonalization method. The properties of this model are determined by the ratio of two interactions, namely,…
The ground state of the spin-$1/2$ Heisenberg antiferromagnet on a distorted triangular lattice is studied using a numerical-diagonalization method. The network of interactions is the $\sqrt{3}\times\sqrt{3}$ type; the interactions are…
Neutron diffraction on the double perovskite Sr2YRuO6 with a quasi-face-centered cubic (FCC) lattice of Ru moments reveals planar magnetic correlations that condense into a partial long-range ordered state with coupled alternate…
The magnetic properties of Cs$_2$Cu$_3$CeF$_{12}$ were investigated through magnetization and specific heat measurements. Cs$_2$Cu$_3$CeF$_{12}$ is composed of a buckled kagome lattice of Cu$^{2+}$, which is stacked along the b axis. The…
In this paper, we study the influence of spatial fluctuations in a two-dimentional Kondo-Lattice model (KLM) with anti-ferromagnetic couplings. To accomplish this, we first present an implementation of the dual-fermion (DF) approach based…
We investigate quantum phase transitions for the $s=1/2$ antiferromagnetic Heisenberg model on a pyrochlore lattice. By means of a series expansion starting from isolated tetrahedra, the ground-state phase diagram is determined. When the…
Quantum phase transition from the N\'eel to the dimer states in an antiferromagnetic(AF) Heisenberg model on square lattice is studied. We introduce a control parameter $\alpha$ for the exchange coupling which connects the N\'eel…
We investigate the magnetic behavior of the 6H-perovskite dimer lattice Ba$_3$Zn$_{1-x}$Ca$_x$Ru$_2$O$_9$ using analytical theory, density functional theory, inelastic neutron scattering, and modeling of historical magnetization and…
Short-range resonating-valence bond states in an orbitally degenerate magnet on a honeycomb lattice is studied. A quantum-dimer model is derived from the Hamiltonian which represents the superexchange interaction and the dynamical…
Ferroelectric control of altermagnetism in momentum space has been studied widely, while the control of magnetism in real space of altermagnets are still rare. We present a design rule to identify multiferroicity in n=2 Ruddlesden-Popper…
We performed variational calculation based on the multi-scale entanglemnt renormalization ansatz, for the antiferromagnetic Heisenberg model on a Shastry Sutherland lattice (SSL). Our results show that at coupling ratio J'/J= 0.687(3), the…
We study a two-dimensional (2D) spin-half Heisenberg model related to the quasi 2D antiferromagnets (Ba,Sr)2Cu3O4Cl2 by means of exact diagonalization and spin-wave theory. The model consists of two inequivalent interpenetrating…
We study a ferromagnetic Heisenberg spin system on the square lattice, with nearest neighbors interaction J_1 frustrated by second J_2 and third J_3 neighbors antiferromagnetic interactions, using a mean field theory for the Schwinger boson…
High temperature one-dimensional (1D) ferromagnetic (FM) chains in Ca3Co2O6 spin system are subjected to a magnetic field and temperature induced first order phase transition (FOPT) to 3D ferrimagnetic (FIM) ground state with decrease in…