Ground-state magnetic properties of spin ladder-shaped quantum nanomagnet: Exact diagonalization study

TL;DR

This study uses exact diagonalization to analyze the ground-state magnetic properties of a finite two-legged quantum spin ladder nanomagnet with variable interactions and external magnetic field.

Contribution

It provides a detailed phase diagram and comparison of ferro- and antiferromagnetic couplings for a specific quantum spin ladder system.

Findings

Ground-state phase diagram mapped as a function of interactions and magnetic field

Ground-state energy and spin-spin correlations characterized

Differences between ferro- and antiferromagnetic couplings analyzed

Abstract

The paper presents a computational study of the ground-state properties of a quantum nanomagnet possessing the shape of a finite two-legged ladder composed of 12 spins $S=1/2$. The system is described with isotropic quantum Heisenberg model with nearest-neighbour interleg and intraleg interactions supplemented with diagonal interleg coupling between next nearest neighbours. All the couplings can take arbitrary values. The description of the ground state is based on the exact numerical diagonalization of the Hamiltonian. The ground-state phase diagram is constructed and analysed as a function of the interactions and the external magnetic field. The ground-state energy and spin-spin correlations are extensively discussed. The cases of ferro- and antiferromagnetic couplings are compared and contrasted.