Related papers: Magnetization plateau in a two-dimensional multipl…
Very recently a non-trivial magnetization plateau at 1/4 of the saturation magnetization was observed in the S=1 spin ladder BIP-TENO. In our previous work we proposed a possible mechanism of the plateau based on the second- and…
The ground state, magnetization scenario and the local bipartite quantum entanglement of a mixed spin-$1/2$ Ising--Heisenberg model in a magnetic field on planar lattices formed by identical corner-sharing bipyramidal plaquettes is examined…
A full energy spectrum of the spin-1/2 Heisenberg cubic cluster is used to investigate a low-temperature magnetization process and adiabatic demagnetization of this zero-dimensional 2x2x2 quantum spin system. It is shown that the…
The Heisenberg model on a face center cubic (fcc) lattice is a typical three-dimensional frustrated spin system expected to have magnetization plateaus and supersolid phases. There are model compounds $A_2$CoTeO$_6$ ($A$ = Ca, Sr, Pb) for…
We use a combination of density matrix renormalization group calculations and analytical approaches to study a simplified model for a spatially anisotropic spin-1/2 triangular lattice Heisenberg antiferromagnet: the three-leg triangular…
We study ring-exchange models for bosons or XY-spins on the triangular lattice. A four-spin exchange leads to a manifold of ground states with gapless excitations and critical power-law correlations. With a nearest-neighbour exchange,…
We study the magnetic field dependence of the ground state of $S=1/2$ $J_1$-$J_2$ Heisenberg model on the square lattice by the DMRG method with the sine-square deformation. We obtain 8 different phases including plaquette valence-bond…
We present numerical evidence that the spin-1/2 Heisenberg model on the two-dimensional checkerboard lattice exhibits several magnetization plateaux for m=0, 1/4, 1/2 and 3/4, where m is the magnetization normalized by its saturation value.…
We study the spin-1/2 two-leg Heisenberg ladder with four-spin ring exchanges under a magnetic field. We introduce an exact duality transformation which is an extension of the spin-chirality duality developed previously and yields a new…
We present an extensive overview of the phase diagram, spin-wave excitations, and finite-temperature transitions of the anisotropic-exchange magnets on an ideal nearest-neighbor triangular lattice. We investigate transitions between five…
We report on a comprehensive thermodynamic study of a quasi-two-dimensional (quasi-2D) quantum magnet Cu$_2$(OH)$_3$Br which in the 2D layer can be viewed as strongly coupled alternating antiferromagnetic and ferromagnetic chains. In an…
We study an anisotropic Heisenberg antiferromagnet with ferromagnetic transverse spin exchange using exact quantum Monte Carlo methods. Such a model is relevant to a class of rare earth tetraboride materials that display a range of…
We determine the quantum phase diagram of the antiferromagnetic spin-1/2 XXZ model on the triangular lattice as a function of magnetic field and anisotropic coupling $J_z$. Using the density matrix renormalization group (DMRG) algorithm in…
Motivated by the low temperature magnetization curves of several spinel chromites, we theoretically study classical mechanisms of degeneracy lifting in pyrochlore antiferromagnets. Our main focus is on the coupling of spin exchange to…
The two-dimensional (2D) spin-1/2 kagome Heisenberg antiferromagnet is believed to host quantum spin liquid (QSL) states with no magnetic order, but its ground state remains largely elusive. An important outstanding question concerns the…
We investigate the S=1/2 antiferromagnetic Heisenberg model with a 3$\times$3 checkerboard lattice structure in a longitudinal magnetic field. By using the stochastic series expansion quantum Monte Carlo (SSE-QMC) method, we obtain the…
The stability of the magnetization $m=1/3$ plateau phase of the XXZ spin-1/2 Heisenberg chain with competing interactions is investigated upon switching on a staggered transverse magnetic field. Within a bosonization approach, it is shown…
We find unconventional Mott insulators in a quasi-2D version of the Shastry-Sutherland model in a magnetic field. In our realization on a 4-leg tube geometry, these are stabilized by correlated hopping of localized magnetic excitations.…
K$_2$Ni$_2$(SO$_4$)$_3$ is a member of the langbeinite family, consisting of two intertwined $S=1$ trillium lattices, out of which one is strongly coupled (strong-TL) and the other is weakly coupled (weak-TL). Further inter-trillium…
The quantum spin ice model applied to Tb2Ti2O7 predicts that magnetic fields applied along the [111] axis will induce a partial magnetization plateau [H. R. Molavian and M. J. P. Gingras, J. Phys.: Condens. Matter 21, 172201 (2009)]. We…