Magnetic Properties of J-J-J' Quantum Heisenberg Chains with Spin S=1/2, 1, 3/2 and 2 in a Magnetic Field

TL;DR

This study uses DMRG to explore how magnetic properties and magnetization plateaus in J-J-J' quantum Heisenberg chains vary with different spins, couplings, and magnetic fields, revealing critical points where plateaus vanish.

Contribution

It provides a detailed analysis of magnetization plateaus in J-J-J' chains with various spins, highlighting the effects of ferromagnetic and antiferromagnetic couplings and the absence of fundamental differences between half-integer and integer spins.

Findings

Plateaus decrease in width with increasing ferromagnetic coupling.

Plateaus disappear when the ratio exceeds a critical value.

No fundamental difference between half-integer and integer spins.

Abstract

By means of the density matrix renormalization group (DMRG) method, the magnetic properties of the J-J-J$^{\prime}$ quantum Heisenberg chains with spin $S=1/2$, 1, 3/2 and 2 in the ground states are investigated in the presence of a magnetic field. Two different cases are considered: (a) when $J$ is antiferromagnetic and $J^{\prime}$ is ferromagnetic (i.e. the AF-AF-F chain), the system is a ferrimagnet. The plateaus of the magnetization are observed. It is found that the width of the plateaus decreases with increasing the ferromagnetic coupling, and disappears when $% J^{\prime}/J$ passes over a critical value. The saturated field is observed to be independent of the ferromagnetic coupling; (b) when $J$ is ferromagnetic and $J^{\prime}$ is antiferromagnetic (i.e. the F-F-AF chain), the system becomes an antiferromagnet. The plateaus of the magnetization are also seen. The width of the plateaus decreases with decreasing the antiferromagnetic coupling, and disappears when $J^{\prime}/J $ passes over a critical value. Though the ground state properties are quite different, the magnetization plateaus in both cases tend to disappear when the ferromagnetic coupling becomes more dominant. Besides, no fundamental difference between the systems with spin half-integer and integer has been found.