Related papers: Cluster expansion for dimerized spin systems
Many low dimensional spin systems with a dimerized or ladder-like antiferromagnetic exchange coupling have a gapped excitation spectrum with magnetic bound states within the spin gap. For spin ladders with an even number of legs the…
The quasi-two-dimensional Heisenberg spin $S=1/2$ dimer system bis(2-amino-5-fluoro-pyridinium) tetrachlorocuprate(II) is studied by means of inelastic neutron scattering, calorimetry and nuclear magnetic resonance (NMR) experiments. In the…
Pinning and depinning of wavefronts are ubiquitous features of spatially discrete systems describing a host of phenomena in physics, biology, etc. A large class of discrete systems is described by overdamped chains of nonlinear oscillators…
We investigate the onset of the discontinuous percolation transition in small-world hyperbolic networks by studying the systems-size scaling of the typical largest cluster approaching the transition, $p\nearrow p_{c}$. To this end, we…
In a recent inelastic neutron scattering experiment in the pseudogap state of the high temperature superconductor $\mathrm{YBa_{2}Cu_{3}O_{6.6}}$ an unusual `vertical' dispersion of the spin excitations with a large in-plane anisotropy was…
We show that short-range correlations have a dramatic impact on the steady-state phase diagram of quantum driven-dissipative systems. This effect, never observed in equilibrium, follows from the fact that ordering in the steady state is of…
Inelastic neutron scattering is used to study transverse-polarized magnetic excitations in the quasi-one-dimensional S=1/2 antiferromagnet BaCu_2Si_2O_7, where the saturation value for the N\'eel order parameter is $m_0=0.12 \mu_{\rm B}$…
In general we are interested in dynamical systems coupled to complex hysteresis. Therefore as a first step we investigated recently the dynamics of a periodically driven damped harmonic oscillator coupled to independent Ising spins in a…
We present results on the dynamics of the distorted diamond chain, S=1/2 dimers alternating with single spins 1/2 and exchange couplings $J_1$ and $J_3$ in between. The dynamics in the spin fluid (SF) and tetramer-dimer (TD) phases is…
A system of degenerate drift-diffusion equations for the electron, hole, and oxygen vacancy densities, coupled to the Poisson equation for the electric potential, is analyzed in a three-dimensional bounded domain with mixed…
A microscopic understanding of the strongly correlated physics of the cuprates must account for the translational and rotational symmetry breaking that is present across all cuprate families, commonly in the form of stripes. Here we…
An averaging procedure is proposed to account for spectral features of correlated one-dimensional systems in the presence of non-magnetic impurities. The dynamical spin structure factor for a corresponding random ensemble of Heisenberg…
The ground state of the square lattice bilayer quantum antiferromagnet with nearest ($J_1$) and next-nearest ($J_2$) neighbour intralayer interaction is studied by means of the dimer expansion method up to the 6-th order in the interlayer…
The isotropic Heisenberg chain represents a particular case of an integrable many-body system exhibiting superdiffusive spin transport at finite temperatures. Here, we show that this model has distinct properties also at finite…
Correlation-driven metal-insulator transitions and temperature-driven quantum-coherent-to-incoherent crossovers in correlated electron systems underpin the doping, temperature and frequency-resolved evolution of physical responses.…
A Dirac quantum spin liquid hosts Dirac spinons, which are low-energy fractionalized neutral quasiparticles with spin 1/2 that obey the Dirac equation. Recent inelastic neutron scattering studies have revealed a cone spin continuum in…
We study the zero-temperature spin fluctuations of a two-dimensional itinerant-electron system with an incommensurate magnetic ground state described by a single-band Hubbard Hamiltonian. We introduce the (broken-symmetry) magnetic phase at…
In this work the systems composed of particles interacting with hard potential are investigated. These systems feature certain modifications to the crystal structure - selected particles are replaced with ones that differ slightly in their…
We study the dynamics of waves in a system of diffusively coupled discrete nonlinear sources. We show that the system exhibits burst waves which are periodic in a traveling-wave reference frame. We demonstrate that the burst waves are…
We investigate energy diffusion in long-range interacting spin systems, where the interaction decays algebraically as $V(r) \propto r^{-\alpha}$ with the distance $r$ between the sites. We consider prototypical spin systems, the transverse…