UNIQUENESS AND DEGENERACY OF GROUND STATES FOR SOME QUANTUM SPIN CHAINS

APPLICATIONS OF FINITELY CORRELATED STATES TO THE GROUND STATE PROBLEM OF QUANTUM SPIN CHAINS

PHASE TRANSITIONS IN QUANTUM SPIN CHAINS

THE QUANTUM TRANSFER MATRIX AND ITS APPLICATION TO QUANTUM SPIN CHAINS

q-DEFORMATIONS OF QUANTUM SPIN CHAINS WITH EXACT VALENCE–BOND GROUND STATES

Construction and study of exact ground states of quantum spin chains

Uniqueness of the translationally invariant ground state in quantum spin systems