Staggered magnetization and entanglement enhancement by magnetic impurities in $S=1/2$ spin chain

TL;DR

This paper investigates how magnetic impurities influence magnetization and entanglement in a $S=1/2$ spin chain, revealing oscillating behaviors and potential for controlled entanglement manipulation at zero and finite temperatures.

Contribution

It demonstrates the impact of magnetic impurities on magnetization oscillations and entanglement, proposing a method for adiabatic control of entanglement distribution in spin chains.

Findings

Oscillating magnetization decays as a power law from the impurity.

Entanglement is either enhanced or quenched depending on impurity position.

Results are robust against temperature variations.

Abstract

We study the effects of a magnetic impurity on the behavior of a $S=1/2$ spin chain. At T=0, both with and without an applied uniform magnetic field, an oscillating magnetization appears, whose decay with the distance from the impurity is ruled by a power law. As a consequence, pairwise entanglement is either enhanced or quenched, depending on the distance of the spin pair with respect to the impurity and on the values of the magnetic field and the intensity of the impurity itself. This leads us to suggest that acting on such control parameters, an adiabatic manipulation of the entanglement distribution can be performed. The robustness of our results against temperature is checked, and suggestions about possible experimental applications are put forward.