Related papers: Factorized ground state for a general class of fer…
A coupled spin-electron diamond chain with localized Ising spins placed on its nodal sites and mobile electrons delocalized over interstitial sites is explored in a magnetic field taking into account the difference between Land\'e g-factors…
We study the ground state properties of a quantum antiferromagnet in the kagome lattice in the presence of a magnetic field, paying particular attention to the stability of the plateau at magnetization 1/3 of saturation. While the plateau…
We propose a novel two-dimensional (2D)frustrated quantum spin-1/2 anisotropic Heisenberg model with alternating ferromagnetic and antiferromagnetic magnetic chains along one direction and antiferromagnetic interactions along the other. The…
Octahedral antiferromagnets are distinguished by crystal lattices composed of octahedra of magnetic ions. In the fully frustrated case, the Heisenberg Hamiltonian can be represented as a sum of squares of total spins for each octahedral…
Ground-state properties of the Blume-Emery-Griffiths model with antiferromagnetic nearest-neighbor interactions on a triangular lattice are investigated in the presence of an external magnetic field. In particular, we explore the model's…
Ground-state magnetization curves of ferrimagnetic Heisenberg chains of alternating spins $S$ and $s$ are numerically investigated. Calculating several cases of $(S,s)$, we conclude that the spin-$(S,s)$ chain generally exhibits $2s$…
We study the ground state properties of a quantum antiferromagnet on the kagome lattice in the presence of a magnetic field, paying particular attention to the stability of the plateau at magnetization 1/3 of saturation and the nature of…
We study ferrimagnetism in the ground state of the antiferromagnetic Heisenberg model on the spatially anisotropic kagome lattice, in which ferrimagnetism of the conventional Lieb-Mattis type appears in the region of weak frustration…
We examine the ground state of a Heisenberg model with arbitrary spin S on a one-dimensional lattice composed of diamond-shaped units. A unit includes two types of antiferromagnetic exchange interactions which frustrate each other. The…
We have found the exact ground state for two electronic models on a linear chain. The first model describes half-filling electron system in the ferromagnet--antiferromagnet transition point. In the singlet ground state the spin correlators…
We consider a mixture of two species of spin-1 atoms with both interspecies and intraspecies spin exchanges in a weak magnetic field. Under the usual single mode approximation, it can be reduced to a model of coupled giant spins. We find…
The ground state properties of the high spin Heisenberg chains with alternating single site anisotropy are investigated by means of the numerical exact daigonaization and DMRG method. It is found that the ferrimagnetic state appears between…
The two-layer square lattice quantum antiferromagnet with spins 1/2 shows a zero-field magnetic order-disorder transition at a critical ratio of the inter-plane to intra-plane couplings. Adding a uniform magnetic field tunes the system to…
We predict that an external field can induce a spin order in highly frustrated classical Heisenberg magnets. We find analytically stabilization of collinear states by thermal fluctuations at a one-third of the saturation field for kagome…
We study the nearest-neighbor Heisenberg antiferromagnet on a face-centered cubic lattice with arbitrary spin S. The model exhibits degenerate classical ground states including two collinear structures AF1 and AF3 described by different…
The influence of disorder and interaction on the ground state polarization of the two-dimensional (2D) correlated electron gas is studied by numerical investigations of unrestricted Hartree-Fock equations. The ferromagnetic ground state is…
Ground states of the frustrated spin-1 Ising-Heisenberg two-leg ladder with Heisenberg intra-rung coupling and only Ising interaction along legs and diagonals are rigorously found by taking advantage of local conservation of the total spin…
Making use of exact results and quantum Monte Carlo data for the entanglement of formation, we show that the ground state of anisotropic two-dimensional S=1/2 antiferromagnets in a uniform field takes the classical-like form of a product…
We present a theory of the realization of a ferromagnetic Haldane state in a spin-2 bilinear-biquadratic spin system on an orthogonal-dimer chain. The coexistence of a ferromagnetic state and a Haldane state is due to the rigorous…
We study numerically the ground state properties of the one-dimensional quarter-filled strongly correlated electronic system interacting antiferromagnetically with localized $S=1/2$ spins. It is shown that the charge-ordered state is…