The past decade has witnessed an explosion in the field of quantum materials, headlined by
the predictions and discoveries of novel Landau-symmetry-broken phases in correlated …

The magnetic energy levels of a given magnetic solid are closely packed in energy because
the interactions between magnetic ions are weak. Thus, in describing its magnetic …

Frustration in magnetic materials arising from competing exchange interactions can prevent
the system from adopting long-range magnetic order and can instead lead to a diverse …

Abstract The Bose–Einstein condensate (BEC) is a fascinating state of matter predicted to
occur for particles obeying Bose statistics. Although the BEC has been observed with …

There is a long time gap between the formulation of the basic theory of low-dimensional (low-
D) magnetism as advanced by Ising, Heisenberg and Bethe and its experimental …

Magnetic insulators have proved to be fertile ground for studying new types of quantum
many-body state, and I survey recent experimental and theoretical examples. The insights …

This article reviews experimental and theoretical work on Bose-Einstein condensation in
quantum magnets. These magnets are natural realizations of gases of interacting bosons …

Paramagnets on the border of ferromagnetism at low temperatures are more subtle and
complex than anticipated by the conventional theory of quantum critical phenomena. Could …

A theoretical overview of the phenomenon of spontaneous magnon decays in quantum
antiferromagnets is presented. The intrinsic zero-temperature damping of magnons in …

Perturbation series expansion methods are sophisticated numerical tools used to provide
quantitative calculations in many areas of theoretical physics. This book gives a …