An overview of one-and two-dimensional quantum spin systems based on transition-metal
oxides and halides of current interest is given, such as spin-Peierls, spin-dimer …

The density matrix renormalization group (DMRG) has become a powerful numerical
method that can be applied to low-dimensional strongly correlated fermionic and bosonic …

Abstract The Dzyaloshinski-Moriya interaction partially lifts the magnetic frustration of the
spin-1/2 oxide SrCu 2 (BO 3) 2. It explains the fine structure of the excited triplet state and its …

Raman light scattering of the two-dimensional quantum spin system SrCu 2 (BO 3) 2 shows
a rich structure in the magnetic excitation spectrum, including several well-defined bound …

Transition metal oxides that realize s= 1/2 or s= 1 quantum spin systems with low
dimensionality or geometrically restricted connectivity are often described using simple …

We present a new linked cluster expansion for calculating properties of multiparticle
excitation spectra to high orders. We use it to obtain the two-particle spectra for systems of …

A simple intuitive picture of spin-Peierls antiferromagnets arises from regarding the
elementary excitations as S= 1/2 solitons. We investigate these excitations numerically in a …

The excitation spectrum of the two-chain S= 1/2 Heisenberg spin ladder with additional
second neighbor frustrating interactions is studied by a variety of techniques. A description …

We consider the ground-state phase diagram of a one-dimensional spin-1/2 XXZ chain with
a spatially modulated Dzyaloshinskii-Moriya interaction in the presence of an alternating …

Neutron-scattering experiments on (VO) 2 P 2 O 7 reveal both a gapped magnon dispersion
and an unexpected, low-lying second mode. The proximity and intensity of these modes …