The spin-½ antiferromagnetic Heisenberg model on a square lattice is used to describe the
dynamics of the spin degrees of freedom of undoped copper oxides. Even though the model …

The Hubbard model is ahighly oversimplified model'for electrons in a solid which interact
with each other through extremely short-ranged repulsive (Coulomb) interaction. The …

We discuss a method of numerically identifying exact energy eigenstates for a finite system,
whose form can then be obtained analytically. We demonstrate our method by identifying …

This is a self-contained advanced textbook on quantum many-body systems, which is
intended to be accessible to students and researchers in physics, mathematics, quantum …

Quantum many-body scar states are many-body states with finite energy density in non-
integrable models that do not obey the eigenstate thermalization hypothesis. Recent works …

We study a construction that yields a class of translation invariant states on quantum spin
chains, characterized by the property that the correlations across any bond can be modeled …

The family of layered organic salts X [Pd (dmit) 2] 2 are Mott insulators and form scalene-
triangular spin-1∕ 2 systems. Among them, Et Me 3 Sb [Pd (dmit) 2] 2 has a nearly regular …

Exact spectra of periodic samples are computed up to N= 36. Evidence of an extensive set of
low-lying levels, lower than the softest magnons, is exhibited. These low-lying quantum …

To gain insight into the behavior of the Hubbard model, we define a SU (n) invariant
generalization of the Hubbard-Heisenberg model and, in the large-n limit, solve it in one …

A modified spin-wave theory for the Heisenberg antiferromagnet (scrH= J) is formulated
under the assumption of zero sublattice magnetization in the same way with the Heisenberg …