Frustration-Induced Ferrimagnetism in Heisenberg Spin Chains

TL;DR

This paper investigates the ground-state properties of frustrated Heisenberg spin chains, revealing ferrimagnetism in systems with different spin magnitudes and suggesting that multi-sublattice structures are not necessary for ferrimagnetism in quantum spin systems.

Contribution

It demonstrates ferrimagnetism in S=1 and S=1/2 Heisenberg chains without multi-sublattice structures, challenging previous assumptions.

Findings

Ferrimagnetism occurs in both S=1/2 and S=1 chains.

Multi-sublattice structure is not required for ferrimagnetism.

Numerical methods used include exact diagonalization and DMRG.

Abstract

We study ground-state properties of the Heisenberg frustrated spin chain with interactions up to fourth nearest neighbors by the exact-diagonalization method and the density matrix renormalization group method. We find that ferrimagnetism is realized not only in the case of S=1/2 but also S=1 despite that there is only a single spin site in each unit cell determined from the shape of the Hamiltonian. Our numerical results suggest that a "multi-sublattice structure" is not required for the occurrence of ferrimagnetism in quantum spin systems with isotropic interactions.