Spin-Gap States of a Periodic Mixed Spin Chain

Abstract

We examine a chain of periodic arrays of 4 quantum spins with magnitudes of 1/2, 1, 3/2 and 1. There are four kinds of nearest-neighbour exchange parameters among them. We choose two independent parameters for concreteness: one represents the ratio of typical exchange parameters, and the other represents a distortion. We determine the phase diagram of the ground state in the parameter space. The phase boundaries appear as gapless lines which separate gapful disordered phases. They are determined by the gapless equation which was previously derived by mapping a general periodic spin chain to the nonlinear $\sigma$ model.

5 pages (5 figures included) Submitted to Journal of Physics and Chemistry of Solids (Proceedings of CREST International Workshop)

References in corpus (6)

• Alternating spin chains with singlet ground states
• Ground-State and Thermodynamic Properties of the Quantum Mixed Spin-1/2-1/2-1-1 Chain
• Non-Linear Sigma Model for Inhomogeneous Spin Chains
• Phase Diagrams of Mixed Spin Chains with Period 4 by the Nonlinear $\sigma$ Model
• Ground State Properties of One Dimensional S=1/2 Heisenberg Model with Dimerization and Quadrumerization
• Phase Diagram of the 1/2-1/2-1-1 Spin Chain by the Nonlinear Sigma Model

Cited by in corpus (2)

• Frustration Induced Quantum Phases in Mixed Spin Chain with Frustrated Side Chains
• Disordered ground states in a quantum frustrated spin chain with side chains