We review ground states and excitations of a quantum antiferromagnet on triangular and
other frustrated lattices. We pay special attention to the combined effects of magnetic field h …

We review two important non-perturbative approaches for extracting the physics of low-
dimensional strongly correlated quantum systems. Firstly, we start by providing a …

The density-matrix renormalization group method (DMRG) has established itself over the
last decade as the leading method for the simulation of the statics and dynamics of one …

We study the one-dimensional spin-1/2 Heisenberg chain with competing ferromagnetic
nearest-neighbor J 1 and antiferromagnetic next-nearest-neighbor J 2 exchange couplings …

We present the phase diagram of the frustrated ferromagnetic S= 1 2 Heisenberg J 1− J 2
chain in a magnetic field, obtained by large scale exact diagonalizations and density matrix …

Motivated by experiments on Josephson junction arrays, and cold atoms in an optical lattice
in a synthetic magnetic field, we study the “fully frustrated” Bose-Hubbard model with half a …

Motivated by experiments on Josephson junction arrays in a magnetic field and ultracold
interacting atoms in an optical lattice in the presence of a “synthetic” orbital magnetic field …

In the last two decades, significant progress has been made in combining ferroelectricity and
magnetism in the same material. Usually, magnetism and ferroelectricity were thought of as …

Waveguide QED has emerged as a powerful analog quantum simulator due to the
possibility of mediating versatile spin-spin interactions with tunable sign, range, and even …

We study the excitation spectrum and dynamical response functions for several quasi-one-
dimensional spin systems in magnetic fields without dipolar spin order transverse to the …