Related papers: Modulation structure of a frustrated spin ladder
We study the quantum phase transitions of frustrated antiferromagnetic Heisenberg spin-1 systems on the 3/4 and 3/5 skewed two leg ladder geometries. These systems can be viewed as arising by periodically removing rung bonds from a zigzag…
We introduce a one-dimensional (1D) pseudospin model on a ladder where the Ising interactions along the legs and along the rungs alternate between $X_{i}X_{i+1}$ and $Z_{i}Z_{i+1}$ for even/odd bond (rung). We include also the next nearest…
We consider low-energy excitation structures of N-leg integer-spin ladder and tube systems with an antiferromagnetic (AF) intrachain coupling and a uniform external field. The tube means the ladder with the periodic boundary condition along…
Magnetic excitations in two-leg S=1/2 ladders are studied both experimentally and theoretically. Experimentally, we report on the reflectivity, the transmission and the optical conductivity sigma(omega) of undoped La_x Ca_14-x Cu_24 O_41…
Using the density matrix renormalization group technique we investigate the low-energy properties and the magnetization plateau behavior in a 2-leg mixed spin ladder consisting of a spin-1/2 chain coupled with a spin-1 chain. The calculated…
Magnetic excitations of the recently discovered frustrated spin-1/2 two-leg ladder system Li$_2$Cu$_2$O(SO$_4$)$_2$ are investigated using inelastic neutron scattering, magnetic susceptibility and infrared absorption measurements. Despite…
We consider a system of weakly interacting bosons confined on a planar double lattice ring subjected to two artificial gauge fields. This system is known to display three phases, the Meissner phase where the flow of particles is carried at…
We introduce a one-dimensional plaquette orbital model with a topology of a ladder and alternating interactions between $x$ and $z$ pseudospin components along both the ladder legs and on the rungs. We show that it is equivalent to an…
We investigate a highly frustrated spin-1 model on the triangular lattice, with nearest- and next-nearest-neighbor antiferromagnetic $S\cdot S$ interactions and nearest-neighbor $(S\cdot S)^2$ interactions. Using the density matrix…
We study the magnetic orbital effect of a doped two-leg ladder in the presence of a magnetic field component perpendicular to the ladder plane. Combining both low-energy approach (bosonization) and numerical simulations (density-matrix…
The frustrated ladder with alternate ferromagnetic(F) exchange $-J_F$ and AF exchange $J_A$ to first neighbors and F exchange $-J_L$ to second neighbors is studied by exact diagonalization (ED) and density matrix renormalization group…
Two legged skewed spin-$\frac{1}{2}$ ladders are frustrated and exhibit exotic quantum phases in ground state due to strong quantum fluctuations and competing spin exchanges. Here, we study ground state properties of a spin-$\frac{1}{2}$…
Ground-state and finite-temperature phase diagrams of a geometrically frustrated spin-1/2 Ising-Heisenberg model on a triangle-hexagon lattice are investigated within the generalized star-triangle mapping transformation. It is shown that…
Using continuous unitary transformations (CUT) we calculate the one-triplet gap for the antiferromagnetic S=1/2 two-leg spin ladder with additional four-spin exchange interactions in a high order series expansion about the limit of isolated…
We study the excitation spectrum of the two-chain S=1/2 Heisenberg spin ladder with additional inter-chain second-neighbor frustrating interactions. The one and two-particle excitations are analyzed by using a mapping of the model onto a…
We show that non-frustrated and frustrated ladders in a magnetic field can be systematically mapped onto an XXZ Heisenberg model in a longitudinal magnetic field in the limit where the rung coupling is the dominant one. This mapping is…
We analyze the possible existence of topological phases in two-legged spin ladders considering a staggered interaction in both chains. When the staggered interaction in one chain is shifted by one site with respect to the other chain, the…
We study the magnetism of a frustrated four-leg spin-1/2 ladder with transverse periodic boundary conditions: the frustrated four-spin tube (FFST). Using a combination of series expansion (SE), based on the continuous unitary transformation…
The variational cluster approximation is used to study the frustrated Hubbard model at half filling defined on the two-dimensional square lattice with anisotropic next-nearest-neighbor hopping parameters. We calculate the ground-state phase…
By using the series expansion techniques, we study the excitation spectrum for the two-dimensional quantum spin systems with ladder, plaquette and mixed-spin structures. We calculate the spin excitation gap and thus determine the phase…