Effect of three-spin interaction on thermal entanglement in Heisenberg XXZ model

TL;DR

This paper investigates how three-spin interactions influence thermal entanglement in the Heisenberg XXZ model, revealing symmetry breaking, structural shifts, and phase transition-like behavior in entanglement properties.

Contribution

It introduces the analysis of three-spin interactions' effects on thermal entanglement in the XXZ model, highlighting symmetry breaking and entanglement structure changes.

Findings

Three-spin interaction breaks magnetic field symmetry in entanglement.

It shifts and suppresses dip and boot structures in concurrence.

A critical point at |k|=|J| marks a sudden change in entanglement.

Abstract

The effect of three-spin interaction k on thermal entanglement between alternate qubits is studied using pairwise concurrence C and energy level diagram. It is found that k breaks the symmetry about the effect of magnetic field h on C. It shifts a dip structure and gradually effaces a boot structure when |k|<|J| (J is spin exchange coupling). A peak with C maintains 1 appears and expands, elbowing the dip backwards when |k|>|J|. A sudden change of the concurrence occurs around |k|=|J|, h=-k. Similar conclusions about nearest-neighbor qubits are directly given.