Related papers: Dimensional reduction in quantum spin-1/2 system o…
We study the ground state and low-lying excitations of the S=1/2 XXZ antiferromagnet on the kagome lattice at magnetization one third of the saturation. An exponential number of non-magnetic states is found below a magnetic gap. The…
Phase diagram of an Ising-spin Kondo lattice model on a triangular lattice near 1/3-filling is investigated by Monte Carlo simulation. We identify a partially disordered phase with coexistence of magnetic order and paramagnetic moments,…
We present microscopic magnetic properties of a two dimensional triangular lattice Sc2Ga2CuO7, consisting of single and double triangular Cu planes. A Curie-Weiss temperature theta_CW = --44 K and an antiferromagnetic (AFM) exchange…
The ground state phase diagram of the dimerized spin-1/2 XX honeycomb model in presence of a transverse magnetic field (TF) is known. With the absence of the magnetic field, two quantum phases, namely, the N\'eel and the dimerized phases…
On a lattice composed of triangular plaquettes where antiferromagnetic exchange interactions between localized spins cannot be simultaneously satisfied, the system becomes geometrically frustrated with magnetically disordered phases…
The S=2 anisotropic triangular lattice alpha-NaMnO2 is studied by neutron inelastic scattering. Antiferromagnetic order occurs at T ~ 45 K with opening of a spin gap. The spectral weight of the magnetic dynamics above the gap (Delta ~ 7.5…
The magnetocaloric effect is studied at the transition to saturation in the antiferromagnetic spin-1/2 Heisenberg model on the simplest two-dimensional lattices, namely the square and the triangular lattice. Numerical results are presented…
We study the ground-state properties of a family of frustrated spin-1/2 Heisenberg models on two- and three-dimensional decorated lattices composed of connected star-shaped units. Each star is built from edge-sharing triangles with an…
Ising model with quenched random magnetic fields is examined for single Gaussian, bimodal and double Gaussian random field distributions by introducing an effective field approximation that takes into account the correlations between…
Lattice dynamics and magnetic excitations are investigated to elucidate the origin of magneto-dielectric effects in the S=1/2 two-dimensional quantum spin compound K$_2$V$_3$O$_8$. We find evidence for lattice instabilities at 110 K and 60…
We investigate the quantum phases of a frustrated antiferromagnetic Heisenberg spin-1/2 model Hamiltonian on a Kagome-strip chain (KSC), a one-dimensional analogue of the Kagome lattice, and construct its phase diagram in an extended…
Quenched disorder effects on frustrated systems are explored by considering random fluctuations on the antiferromagnetic (AF) interactions between spins on the checkerboard lattice. The replica framework is adopted within a cluster…
We investigate field-induced transformations in the dynamical response of the $XXZ$ model on the triangular lattice that are associated with the anharmonic magnon coupling and decay phenomena. A set of concrete theoretical predictions is…
Geometrical frustration in strongly correlated systems can give rise to a plethora of novel ordered states and intriguing magnetic phases, such as quantum spin liquids. Promising candidate materials for such phases can be described by the…
The widely used Double-Exchange model for manganites is shown to support various "striped" phases at filling fractions 1/n (n=3, 4, 5...), in the previously unexplored regime of narrow bandwidth and small Jahn-Teller coupling. Working in…
Large-spin two-dimensional magnets are generally expected to develop conventional long-range order once the dominant exchange scale becomes appreciable. The layered spin-$3/2$ maple-leaf compound Na$_2$Mn$_3$O$_7$ defies this expectation:…
We present a comprehensive $1/S$ study of the field-induced dynamical properties of the nearest-neighbor $XXZ$ antiferromagnet on a honeycomb lattice using the formalism of the nonlinear spin-wave theory developed for this model. The…
Structural and magnetic properties of a two-dimensional spin-$\frac{5}{2}$ frustrated triangular lattice antiferromagnet NH$_{4}$Fe(PO$_{3}$F)$_2$ are explored via x-ray diffraction, magnetic susceptibility, high-field magnetization, heat…
By means of the recently proposed algorithm based on the tensor product states, the magnetization process of the spin-1/2 anti-ferromagnetic XXZ model on a square lattice is investigated. In the large spin-anisotropy limit, clear evidence…
We have formulated a twist operator argument for the geometrically frustrated quantum spin systems on the kagome and triangular lattices, thereby extending the application of the Lieb-Schultz-Mattis (LSM) and Oshikawa-Yamanaka-Affleck (OYA)…