Influence of a spatial anisotropy on presence of the intermediate one-half magnetization plateau of a spin-1/2 Ising-Heisenberg branched chain

TL;DR

This paper exactly solves a spin-1/2 Ising-Heisenberg branched chain model to explore how spatial anisotropy affects the stability of the one-half magnetization plateau, revealing its dependence on coupling constants and magnetic field.

Contribution

It provides an exact analytical solution for a complex branched chain model, highlighting the impact of anisotropy on magnetization plateaus and phase transitions.

Findings

Anisotropy significantly influences the breakdown of the magnetization plateau.

Three distinct ground states are identified depending on parameters.

The model reveals how coupling constants control phase stability.

Abstract

A spin-1/2 Ising-Heisenberg branched chain constituted by regularly alternating Ising spins and Heisenberg dimers involving an additional side branching is exactly solved in a magnetic field by the transfer-matrix method. The spin-1/2 Ising-Heisenberg branched chain involves two different Ising and one Heisenberg coupling constants. The overall ground-state phase diagram is formed by three different ground states emergent depending on a mutual interplay between the magnetic field and three considered coupling constants: the modulated quantum antiferromagnetic phase, the quantum ferrimagnetic phase, and the classical ferromagnetic phase. It is shown that the interaction anisotropy connected to two different Ising coupling constants substantially influences a breakdown of the intermediate one-half magnetization plateau, which represents a macroscopic manifestation of the quantum ferrimagnetic phase.