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 magnetic susceptibility χ*(t) and specific heat C (t) versus temperature t of the spin S=
1/2 antiferromagnetic (AF) alternating-exchange (J 1 and J 2) Heisenberg chain are studied …

We present results of all-electron electronic-structure calculations for semiconducting
vanadium pentoxide. The calculations are based on density-functional theory within the …

A new x-ray diffraction study of the one-dimensional spin-Peierls compound α′− Na V 2 O 5
reveals a centrosymmetric (Pmmn) crystal structure with one type of V site, contrary to the …

We report 51 V NMR measurements in α′-NaV 2 O 5, which has been considered as a spin-
Peierls (SP) system. Above the transition temperature TC, only one set of V sites was …

An understanding of the effects of electronic correlations in quantum systems is one of the
most challenging problems in physics, partly due to the relevance in modern high …

A quantum Monte Carlo algorithm is constructed starting from the standard perturbation
expansion in the interaction representation. The resulting configuration space is strongly …

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 …

We argue that the origin of the phase transition in quasi-one-dimensional antiferromagnet
NaV2O5 is not the spin-Peierls (SP) instability, but a charge ordering. The opening of the …

The low-temperature superstructure of α′− NaV 2 O 5 is determined by synchrotron
radiation x-ray diffraction. The high-temperature structure is confirmed to be …