The Magnetization of Cu_2(C_5H_{12}N_2)_2Cl_4 : A Heisenberg Spin Ladder System

TL;DR

This paper investigates the magnetic properties of a Heisenberg spin ladder model, applying exact diagonalization to understand phase behavior and relate findings to the experimental copper compound Cu_2(C_5H_{12}N_2)_2Cl_4.

Contribution

It provides a detailed analysis of the magnetization in a Heisenberg spin ladder and correlates theoretical results with experimental data for a specific copper compound.

Findings

Identifies three distinct magnetic phases in the spin ladder model.

Determines the ratio of chain to rung bond strengths (J/J') as approximately 0.2.

Shows ferromagnetic nature of additional diagonal bonds.

Abstract

We study the magnetization of a Heisenberg spin ladder using exact diagonalization techniques, finding three distinct magnetic phases. We consider the results in relation to the experimental behaviour of the new copper compound Cu_2(C_5H_{12}N_2)_2Cl_4 and deduce that the compound is well described by such a model with a ratio of `chain' to `rung' bond strengths (J/J^\prime) of the order of 0.2, consistent with results from the magnetic susceptibility. The effects of temperature, spin impurities and additional diagonal bonds are presented and we give evidence that these diagonal bonds are indeed of a ferromagnetic nature.