Exact Ground States of Frustrated Spin-1 Ising-Heisenberg and Heisenberg Ladders in a Magnetic Field

TL;DR

This paper rigorously determines the ground states of frustrated spin-1 Ising-Heisenberg ladders and compares them with quantum Heisenberg ladders, revealing similar magnetization plateaux at fractional saturation levels.

Contribution

It provides exact ground state solutions for a frustrated spin-1 Ising-Heisenberg ladder and compares these with DMRG results for the quantum Heisenberg ladder, highlighting their similar magnetization behaviors.

Findings

Both models show intermediate magnetization plateaux at 1/4, 1/2, and 3/4 saturation.

Exact solutions are obtained for the Ising-Heisenberg ladder ground states.

The phase diagrams of the two models are qualitatively similar.

Abstract

Ground states of the frustrated spin-1 Ising-Heisenberg two-leg ladder with Heisenberg intra-rung coupling and only Ising interaction along legs and diagonals are rigorously found by taking advantage of local conservation of the total spin on each rung. The constructed ground-state phase diagram of the frustrated spin-1 Ising-Heisenberg ladder is then compared with the analogous phase diagram of the fully quantum spin-1 Heisenberg two-leg ladder obtained by density matrix renormalization group (DMRG) calculations. It is demonstrated that both investigated spin models exhibit quite similar magnetization scenarios, which involve intermediate plateaux at one-quarter, one-half and three-quarters of the saturation magnetization.