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

The idea of exciton condensation in solids was introduced in the 1960s with the analogy of
superconductivity in mind. While exciton supercurrents have been realised only in artificial …

Using the band structure calculation and mean-field analysis of the derived three-chain
Hubbard model with phonon degrees of freedom, we discuss the origin of the orthorhombic …

We show that finite temperature variational cluster approximation (VCA) calculations on an
extended Falicov-Kimball model can reproduce angle-resolved photoemission spectroscopy …

Electrons and holes can spontaneously form excitons and condense in a semimetal or
semiconductor, as predicted decades ago. This type of Bose condensation can happen at …

We report the complex dielectric function of the quasi-one-dimensional chalcogenide Ta 2
NiSe 5, which undergoes a structural phase transition presumably associated with exciton …

Recently we found strong evidence in favor of a BCS-like condensation of excitons in 1 T-
TiSe 2 [Cercellier, Phys. Rev. Lett. 99, 146403 (2007)]. Theoretical photoemission intensity …

We address the lattice deformation of 1 T-TiSe 2 within the exciton condensate phase. We
show that, at low temperature, condensed excitons influence the lattice through electron …

Excitonic insulator (EI) was proposed in the 1960s as a distinct insulating state originating
from pure electronic interaction, but its material realization has been elusive with extremely …

We calculate the critical temperature below which an excitonic insulator exists at the
pressure-induced semiconductor-semimetal transition. Our approach is based on an …