Spin-1/2 Ising-Heisenberg distorted diamond chain with antiferromagnetic Ising and ferromagnetic Heisenberg interactions

TL;DR

This paper presents an exact analysis of a spin-1/2 Ising-Heisenberg distorted diamond chain, revealing complex magnetic behaviors, quantum fluctuation effects, and thermal properties, including magnetization plateaus and multiple specific heat peaks.

Contribution

It introduces an exactly solvable model demonstrating how quantum fluctuations and distortions influence magnetic and thermal properties, including frustration effects.

Findings

Zero-temperature magnetization exhibits intermediate plateaus at 0 and 1/3 saturation.

Multiple peaks in specific heat are observed at various magnetic fields.

Quantum fluctuations induce effective geometrical frustration.

Abstract

The exactly solvable spin-1/2 Ising-Heisenberg distorted diamond chain in the presence of the external magnetic field is investigated for the case of antiferromagnetic Ising and ferromagnetic XXZ Heisenberg interactions. The influence of quantum fluctuations and the distortion on the ground state, magnetic and thermal properties of the model are studied in detail. In particular, it is established that the zero-temperature magnetization curve may involve intermediate plateaus just at zero and 1/3 of the saturation magnetization. It is demonstrated that the temperature dependence of the specific heat reveals up to four distinct peaks at zero magnetic field and up to five distinct peaks at a weak magnetic field. The physical origin of all observed additional peaks of the specific heat has been clarified on the grounds of dominating thermal excitations. We have shown that the quantum fluctuations give rise to an effective geometrical frustration in this chain.