Frustration, Area Law, and Interference in Quantum Spin Models

TL;DR

This paper investigates how frustration affects entanglement scaling in quantum spin models, revealing that high frustration breaks the typical area law, and introduces methods to quantify interference effects and frustration degree.

Contribution

It introduces a novel framework to analyze entanglement in frustrated quantum systems, including a ground state cooling procedure and measures for interference effects.

Findings

Highly frustrated systems violate the area law of entanglement.

Weakly frustrated systems follow an area law similar to nonfrustrated systems.

A new method to quantify constructive and destructive interference in entanglement.

Abstract

We study frustrated quantum systems from a quantum information perspective. Within this approach, we find that highly frustrated systems do not follow any general ''area law'' of block entanglement, while weakly frustrated ones have area laws similar to those of nonfrustrated systems away from criticality. To calculate the block entanglement in systems with degenerate ground states, typical in frustrated systems, we define a ''cooling'' procedure of the ground state manifold, and propose a frustration degree and a method to quantify constructive and destructive interference effects of entanglement.