Related papers: Mixed-Spin Ladders and Plaquette Spin Chains
We investigate the persistence of spectral gaps of one-dimensional frustration free quantum lattice systems under weak perturbations and with open boundary conditions. Assuming the interactions of the system satisfy a form of local…
In a spin glass system on a random graph, some vertices have their spins changing among different configurations of a ground--state domain. Long range frustrations may exist among these unfrozen vertices in the sense that certain…
We investigate Luttinger Liquid superlattices, a periodic structure composed of two kinds of one-dimensional systems of interacting electrons. We calculate several properties of the low-energy sector: the effective charge and spin…
Geometric frustration in quantum spin systems can lead to exotic ground states. In this study, we investigate the $\mathrm{SU}(3)$ spin model on the checkerboard lattice to explore the effects of frustration arising from its point-connected…
The low-dimensional s=1/2 compound (NO)[Cu(NO3)3] has recently been suggested to follow the Nersesyan-Tsvelik model of coupled spin chains. Such a system shows unbound spinon excitations and a resonating valence bond ground state due spin…
In recent years, the study of ladder materials has developed into a well-established area of research within the general context of Strongly Correlated Electrons. This effort has been triggered by an unusual cross-fertilization between…
We study the nature of the ground state of the frustrated J1-J2 model and the J1-J3 model using a variational algorithm based on projected entangled-pair states (PEPS). By investigating spin-spin correlation functions, we observe a…
The low energy electronic spectra of rotationally faulted graphene bilayers are studied using a long wavelength theory applicable to general commensurate fault angles. Lattice commensuration requires low energy electronic coherence across a…
Microscopic models of quantum antiferromagnets are investigated on the basis of a mapping onto effective low energy hamiltonians. Lattice effects are carefully taken into account and their role is discussed. We show that the presence of an…
We consider a spinless $t$-$t'$ ionic Hubbard chain at 1/2 filling and large hopping ratio $t'/t$. In this limit the model adequately maps onto a weakly coupled triangular ladder with a potential interchain bias. The low-energy properties…
A study is presented of a two-dimensional frustrated and dimerized quantum spin-system which models the effect of inter-chain coupling in a spin-Peierls compound. Employing a bond-boson method to account for quantum disorder in the ground…
We clarify an instability of the ground state of the $\Delta$ chain against the lattice distortion that increases a strength $(\lambda)$ of a bond in each triangle. It relaxes the frustration and causes a remarkable gap enhancement; only a…
The non-linear stress-strain relation for crosslinked polymer networks is studied using molecular dynamics simulations. Previously we demonstrated the importance of trapped entanglements in determining the elastic and relaxational…
The extended model of two-leg Ising spin ladder with trimer rungs and next nearest neighbor interaction (NNN) in an external magnetic field is studied using the transfer matrix and linear renormalization group methods. In the standard…
We study the ground state phase diagram of a two dimensional mixed-spin system of coupled alternating spin-1 and $1/2$ chains with a stripe supersolid phase. Utilizing different analytical and numerical approaches such as mean field…
A new quantum spin model with frustration, the `Union Jack' model on the square lattice, is analyzed using spin-wave theory. For small values of the frustrating coupling $\alpha$, the system is N{\' e}el ordered as usual, while for large…
We employ a plaquette basis-generated by coupling the four spins in a $2\times2$ lattice to a well-defined total angular momentum-for the study of Heisenberg ladders with antiferromagnetic coupling. Matrix elements of the Hamiltonian in…
We investigate weakly coupled spin-1/2 ladders in a magnetic field. The work is motivated by recent experiments on the compound (C5H12N)2CuBr4 (BPCB). We use a combination of numerical and analytical methods, in particular the density…
We investigate the low-energy properties of N-leg integer-spin ladders and tubes with an antiferromagnetic (AF) intrachain coupling. In the odd-leg tubes, the AF rung coupling causes the frustration. To treat all ladders and tubes…
Two chains of Luttinger liquids coupled by both interchain hopping and interchain interaction are investigated. A degeneracy of two kinds of dominant states with in phase and out of phase ordering in the absence of the hopping is removed…