Featureless quantum spin liquid, 1/3-magnetization plateau state and exotic thermodynamic properties of spin-1/2 frustrated Heisenberg antiferromagnet on an infinite Husimi lattice

TL;DR

This study uses tensor-network methods to explore the properties of a spin-1/2 Heisenberg antiferromagnet on an infinite Husimi lattice, revealing a gapless, featureless quantum spin liquid with a 1/3-magnetization plateau and exotic thermodynamic behaviors.

Contribution

It provides the first detailed characterization of the ground state and thermodynamics of the spin-1/2 HAF model on an infinite Husimi lattice, highlighting novel quantum spin liquid features.

Findings

Ground state is featureless with exponential decay of correlations.

Presence of a 1/3-magnetization plateau stabilized by quantum fluctuations.

Evidence of a gapless, quantum spin liquid ground state from thermodynamic measurements.

Abstract

By utilizing tensor-network-based methods, we investigate the zero- and finite-temperature properties of the spin-1/2 Heisenberg antiferromagnetic (HAF) model on an infinite Husimi lattice that contains 3/2 sites per triangle. The ground state of this model is found to possess vanishing local magnetization and is featureless; the spin-spin and dimer-dimer correlation functions are verified to decay exponentially; and its ground-state energy per site is determined to be $e_0=-0.4343(1)$, which is very close to that [$e_0=-0.4386(5)$] of the intriguing kagome HAF model. The magnetization curve shows the absence of a zero-magnetization plateau, implying a gapless excitation. A $1/3$-magnetization plateau with spin up-up-down state is observed, which is selected and stabilized by quantum fluctuations. A ground state phase diagram under magnetic fields is presented. Moreover, both magnetic susceptibility and the specific heat are studied, whose low-temperature behaviors reinforce the conclusion that the HAF model on the infinite Husimi lattice owns a gapless and featureless spin liquid ground state.