Magnetization of Antiferromagnetic Cactus Graph Model with Exact Dimer Ground State

TL;DR

This paper investigates the magnetization properties of a quantum spin system on a cactus graph with an exact dimer ground state, revealing complex phases and bound states through analytical methods.

Contribution

It introduces the Cactus Graph Model with an exact dimer ground state and analyzes its magnetization behavior, including density wave and supersolid phases, using an effective boson approach.

Findings

Identification of magnetization plateaus and supersolid phases.

Prediction of multi-triplet bound states due to correlated hopping.

Analysis of singlet-triplet gap and triplet interactions.

Abstract

We introduce and explore the magnetization behavior in a quantum spin system on a cactus graph, deemed the Cactus Graph Model (CGM), featuring an exact dimer singlet ground state. We analyze the singlet-triplet gap, interactions among excited triplets, and correlated hopping under an external magnetic field using a strong coupling expansion. Employing an effective hard-core boson representation, we unveil density wave magnetization plateaus and supersolid phases, revealing the intricate interplay between interactions and hopping dynamics. Furthermore, we conjecture that correlated hopping gives rise to multi-triplet bound states, and potentially engendering to the stabilization of additional low-lying magnetization plateaus.