Related papers: Dynamical Structure Factors for Dimerized Spin Sys…
Dimer models are well known as prototypes for locally constrained physics. They describe systems in which every site on a lattice must be attached to one dimer. Loop models are an extension of this idea, with the constraint that two dimers…
The spectral properties of a disordered system with few interacting three-dimensional spinless fermions are investigated. We show the existence of a critical spacings distribution which is invariant upon increase of the system size, but…
Motivated by recent experiments on Ba$_3$Cr$_2$O$_8$, we propose a theory describing low-temperature properties in magnetic field $h$ of dimer spin-$\frac12$ systems on a stacked triangular lattice with spatially anisotropic exchange…
In the quest for high-spin building blocks to form covalently bonded 1D or 2D materials with controlled magnetic interactions, $\pi$-electron magnetism provides an ideal framework to engineer large ferromagnetic interactions between…
Conventional phonon-electron interaction induces either triplet or one of two (degenerate) singlet pairing states in time reversal and inversion invariant 3D Dirac semi - metal. Investigation of the order parameters and energies of these…
Field-induced magnetic order has been investigated in detail in the interacting spin 3/2 dimer system Cs_3Cr_2Br_9. Elastic and inelastic neutron scattering measurements were performed up to H = 6 T, well above the critical field H_c1 = 1.5…
We study the dynamics of a dimer moving on a periodic one-dimensional substrate as a function of the initial kinetic energy at zero temperature. The aim is to describe, in a simplified picture, the microscopic dynamics of diatomic molecules…
The dynamical dimer structure factor is an observable probing spin-singlet excitations of quantum magnets distinct from those commonly studied by the spin structure factor. We report the dimer response for the extended spin-$1/2$…
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…
In quantum magnetism spin dimers are typically associated with spin-singlet states. To date, $triplet$ $dimerization$ has not been observed in any 3D or quasi-2D material. With this in mind we here discuss the electronic structure of the…
A theory of combined interference and interaction effects on the diffusive transport properties of 3D topological insulator surface states is developed. We focus on a slab geometry (characteristic for most experiments) and show that…
In this paper detailed neutron scattering measurements of the magnetic excitation spectrum of CuCrO$_2$ in the ordered state below $T_{\rm{N1}}=24.2$ K are presented. The spectra are analyzed using a model Hamiltonian which includes…
Inelastic neutron scattering has been applied to the study of the spin dynamics of Cr-based antiferromagnetic octanuclear rings where a finite total spin of the ground state is obtained by substituting one Cr(III) ion (s = 3/2) with Zn (s =…
The site- and bond-dilution effects of the nonmagnetic ground state of a two-dimensional $S=1/2$ antiferromagnetic Heisenberg model, coupled with the lattice distortions on a square lattice, are investigated by performing quantum Monte…
Properties of the depleted Heisenberg spin ladder material series (C$_7$H$_{10}$N)$_2$Cu$_{1-z}$Zn$_{z}$Br$_4$ have been studied by the combination of magnetic measurements and neutron spectroscopy. Disorder-induced degrees of freedom lead…
We provide a theory of triplon dynamics in the valence bond solid ground state of the coupled spin-ladders modelled for BiCu$_2$PO$_6$. Utilizing the recent high quality neutron scattering data [Nature Physics (2015), DOI:…
We examine the dynamics and stripe formation in a system with competing short and long range interactions in the presence of both an applied dc drive and quenched disorder. Without disorder, the system forms stripes organized in a labyrinth…
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…
A recent study [Tassel {\it et al.}, Phys. Rev. Lett. {\bf 105}, 167205 (2010)] has proposed a remarkable spin model for (CuCl)LaNb2O7, in which dimers are ferromagnetically coupled to each other on the distorted Shastry-Sutherland lattice.…
We present the first neutron inelastic scattering results on the low temperature magnetic state of the three dimensional hyperkagom\'e compound Gd$_{3}$Ga$_{5}$O$_{12}$ (GGG). GGG is often classified as a strongly frustrated system with a…