A. Honecker

Macroscopic magnetization jumps due to independent magnons in frustrated quantum spin lattices.

For a class of frustrated spin lattices including the Kagomé lattice we construct exact eigenstates consisting of several independent, localized one-magnon states and argue that they are ground states for high magnetic fields. If the maximal number of local magnons scales with the number of spins in the system, which is the case for the Kagomé lattice, the effect persists in the thermodynamic limit and gives rise to a macroscopic jump in the zero-temperature magnetization curve just below the saturation field. The effect decreases with increasing spin quantum number and vanishes in the classical limit. Thus it is a true macroscopic quantum effect.

Magnetization plateaux in N -leg spin ladders

In this paper we continue and extend a systematic study of plateaux in magnetization curves of antiferromagnetic Heisenberg spin-1/2 ladders. We first review a bosonic field-theoretical formulation of a single

Zero-frequency transport properties of one-dimensional spin-12systems

\mathrm{XXZ}

Magnetization plateaux and jumps in a class of frustrated ladders: A simple route to a complex behaviour

chain in the presence of a magnetic field, which is then used for an Abelian bosonization analysis of

Dynamical signatures of edge-state magnetism on graphene nanoribbons.

N

Multistep approach to microscopic models for frustrated quantum magnets: the case of the natural mineral azurite.

weakly coupled chains. Predictions for the universality classes of the phase transitions at the plateaux boundaries are obtained in addition to a quantization condition for the value of the magnetization on a plateau. These results are complemented by and checked against strong-coupling expansions. Finally, we analyze the strong-coupling effective Hamiltonian for an odd number

Quantum magnetism in two dimensions: From semi-classical Néel order to magnetic disorder

N

Magnetization plateaus in frustrated antiferromagnetic quantum spin models

of cylindrically coupled chains numerically. For

Representations of W-algebras with two generators and new rational models

N=3

MAGNETIZATION CURVES OF ANTIFERROMAGNETIC HEISENBERG SPIN-1/2 LADDERS

we explicitly observe a spin gap with a massive spinon-type fundamental excitation and obtain indications that this gap probably survives the limit