Modified Spin Wave Analysis of Low Temperature Properties of Spin-1/2 Frustrated Ferromagnetic Ladder

TL;DR

This paper uses a modified spin wave approach to analyze the low temperature magnetic properties of a frustrated spin-1/2 ladder, providing results consistent with numerical methods and offering insights near the ferromagnetic ground state boundary.

Contribution

It introduces a modified spin wave analysis for the frustrated ladder, extending understanding of low temperature behavior beyond numerical limitations.

Findings

The method agrees with exact diagonalization in intermediate temperatures.

Modified spin wave provides reliable low temperature results.

Finite size effects are significant in numerical diagonalization.

Abstract

Low temperature properties of the spin-1/2 frustrated ladder with ferromagnetic rungs and legs, and two different antiferromagnetic next nearest neighbor interaction are investigated using the modified spin wave approximation in the region with ferromagnetic ground state. The temperature dependence of the magnetic susceptibility and magnetic structure factors is calculated. The results are consistent with the numerical exact diagonalization results in the intermediate temperature range. Below this temperature range, the finite size effect is significant in the numerical diagonalization results, while the modified spin wave approximation gives more reliable results. The low temperature properties near the limit of the stability of the ferromagnetic ground state are also discussed.