Ground-state phase diagram and magnetization process of the exactly solved mixed spin-(1,1/2) Ising diamond chain

TL;DR

This paper provides an exact solution for the ground-state phases and magnetization process of a mixed spin-(1,1/2) Ising diamond chain, revealing four ground states and a magnetization plateau at half saturation, challenging previous Monte Carlo findings.

Contribution

The study introduces an exact analytical approach using decoration-iteration and transfer-matrix methods for the mixed spin-(1,1/2) Ising diamond chain, clarifying its phase diagram and magnetization behavior.

Findings

Four distinct ground states identified.

Magnetization plateau at half saturation confirmed.

Disproves previous Monte Carlo predictions of additional plateaus.

Abstract

The ground state and magnetization process of the mixed spin-(1,1/2) Ising diamond chain is exactly solved by employing the generalized decoration-iteration mapping transformation and the transfer-matrix method. The decoration-iteration transformation is first used in order to establish a rigorous mapping equivalence with the corresponding spin-1 Blume-Emery-Griffiths chain in a non-zero magnetic field, which is subsequently exactly treated within the framework of the transfer-matrix technique. It is shown that the ground-state phase diagram includes just four different ground states and the low-temperature magnetization curve may exhibit an intermediate plateau precisely at one half of the saturation magnetization. Our rigorous results disprove recent Monte Carlo simulations of Zihua Xin et al. [Z. Xin, S. Chen, C. Zhang, J. Magn. Magn. Mater. 324 (2012) 3704], which imply an existence of the other magnetization plateaus at 0.283 and 0.426 of the saturation magnetization.