Ground-state magnetization curve of a generalized spin-1/2 ladder

TL;DR

This paper uses exact diagonalization to study the ground-state magnetization of a generalized spin-1/2 ladder, revealing a half-plateau phenomenon linked to specific interaction parameters.

Contribution

It introduces a detailed analysis of magnetization plateaus in a spin-1/2 ladder with diagonal interactions, extending understanding of quantum spin systems.

Findings

Half-plateau appears in the magnetization curve within certain interaction ranges.

The results relate to Oshikawa et al.'s condition for plateau formation.

The study connects ladder models to bond-alternating chains.

Abstract

Employing a method of exact diagonalization for finite-size systems, we investigate the magnetization curve in the ground state of an antiferromagnetic spin-1/2 ladder with additional exchange interactions on diagonal bonds, which is equivalent to an antiferromagnetic spin-1/2 chain with bond-alternating nearest-neighbor and uniform next-nearest-neighbor interactions. It is found that a half-plateau appears in the magnetization curve in a certain range of the interaction constants. This result is discussed in connection with the necessary condition for the appearance of the plateau, recently given by Oshikawa et al.