Related papers: Magnetization plateaux induced by a coupling to th…
We study the occurrence of plateaux and jumps in the magnetization curves of a class of frustrated ladders for which the Hamiltonian can be written in terms of the total spin of a rung. We argue on the basis of exact diagonalization of…
We study the spin-3/2 Heisenberg model including easy-plane and exchange anisotropies in one and two dimensions. In the Ising limit, when the off-diagonal exchange interaction J is zero, the phase diagram in magnetic field is characterized…
We study the stability of some strongly frustrated antiferromagnetic spin lattices in high magnetic fields against lattice distortions. In particular, we consider a spin-s anisotropic Heisenberg antiferromagnet on the square-kagom\'{e} and…
We study the $S=1/2$ pyrochlore Heisenberg antiferromagnet in a magnetic field. Using large scale density-matrix renormalization group (DMRG) calculations for clusters up to $128$ spins, we find indications for a finite triplet gap, causing…
We revisit the problem of the spin-Peierls instability in a one dimensional spin-1/2 chain coupled to phonons. The phonons are treated within the mean field approximation. We use bosonization techniques to describe the gapped spin chain and…
This study presents the experimental realization of a spin-1/2 zigzag-square lattice in a verdazyl-based complex, namely ($m$-Py-V-2,6-F$_2$)$[$Cu(hfac)$_2]$. Molecular orbital calculations suggest the presence of five types of frustrated…
In antiferromagnets, the interplay of spin frustration and spin-lattice coupling has been extensively studied as the source of complex spin patterns and exotic magnetism. Here, we demonstrate that, although neglected in the past, the…
For the model of frustrated spin-1/2 Heisenberg magnet described in A. A. Nersesyan and A. M. Tsvelik, (Phys. Rev. B{\bf 67}, 024422 (2003)) we calculate correlation functions of staggered magnetization and dimerization. The model is…
The low temperature magnetization process of antiferromagnetic spin-S chains doped with mobile spin-(S-1/2) carriers is studied in an exactly solvable model. For sufficiently high magnetic fields the system is in a metallic phase with a…
The ground-state properties of the S=1/2 frustrated Heisenberg spin chain with interactions up to fourth nearest neighbors are investigated by the exact-diagonalization method and density matrix renormalization group method. Our numerical…
The S = 1/2 Heisenberg antiferromagnet on the two-dimensional pyramid lattice is studied by the numerical-diagonalization method. This lattice is obtained by the combination of the Lieb lattice and the square lattice. It is known that when…
We study numerically the formation of magnetization plateaux with the Lanczos method in 2-leg ladders with mixed spins of magnitudes $(S_1,S_2)=(1,1/2)$ located at alternating positions along the ladder and with dimerization $\gamma$. For…
We propose an efficient numerical method to obtain local order parameter in two-dimensional systems using spiral boundary conditions. As a benchmark, we first estimate the magnitude of staggered magnetization for the $S=1/2$ XXZ Heisenberg…
We present the phase diagram in a magnetic field of a 2D isotropic Heisenberg antiferromagnet on a triangular lattice. We consider spin-$S$ model with nearest-neighbor ($J_1$) and next-nearest-neighbor ($J_2$) interactions. We focus on the…
The magnetic phase diagram of a plaquette dimerized antiferromagnetic system is studied by using a combination of numerical and analytical techniques. For the strongly frustrated regime, series expansions and bond operators techniques are…
We extend previous analytical studies of the ground-state phase diagram of a one-dimensional Heisenberg spin chain coupled to optical phonons, which for increasing spin-lattice coupling undergoes a quantum phase transition from a gap-less…
The Ising chain consisting of the antiferromagneticaly coupled ferromagnetic trimer is considered in the external magnetic field. In the framework of the transfer-matrix formalism the thermodynamics of the system is described. The…
We discuss our numerical results on the properties of the S = 1/2 frustrated J1-J2 Heisenberg model on a square lattice as a function of temperature and frustration angle phi = atan(J2/J1) in an applied magnetic field. We cover the full…
We theoretically investigate spin-lattice coupling (SLC) effects on the in-field ordering properties of classical Heisenberg antiferromagnets on the breathing pyrochlore lattice. Here, we use the two possible simplified models describing…
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…