Entanglement and the Interplay between Staggered Fields and Couplings

TL;DR

This paper explores how staggered magnetic fields and couplings influence entanglement and quantum phase transitions in a spin system, revealing that increasing alternation can enhance entanglement at various temperatures.

Contribution

It provides an analytical study of entanglement behavior under staggered fields and couplings, identifying quantum phase transitions and their impact on entanglement.

Findings

Two quantum phase transitions identified.

Entanglement increases with stronger staggered fields and couplings.

Entanglement behavior reflects quantum phase transitions at zero temperature.

Abstract

We investigate how the interplay between a staggered magnetic field and staggered coupling strength affects both ground state and thermal entanglement. Upon analytically calculating thermodynamic quantities and the correlation functions for such a system, we consider both the global Meyer-Wallach measure of entanglement and the concurrence between pairs of spins. We discover two quantum phase transitions present in the model and show that the quantum phase transitions are reflected in the behaviour of the entanglement at zero temperature. We discover that increasing the alternating field and alternating coupling strength can actually increase the amount of entanglement present at both zero temperature and for thermal states of the system.