Renormalized quantum Fisher information manifestation of Berezinskii-Kosterlitz-Thouless phase transition for spin-1/2 XXZ chain

TL;DR

This paper investigates the Berezinskii-Kosterlitz-Thouless phase transition in a spin-1/2 XXZ chain using quantum Fisher information and renormalization group methods, revealing universal critical behavior and its relation to entanglement.

Contribution

It introduces a novel approach combining quantum Fisher information with renormalization group techniques to analyze phase transitions in quantum spin chains.

Findings

Quantum Fisher information exhibits universal critical exponent beta=0.47.

Similar behaviors of quantum Fisher information are observed for whole and partial system measurements.

The results align with those obtained by renormalized concurrence and discord.

Abstract

Combining the ideas of quantum Fisher information and quantum renormalization group method, the Berezinskii-Kosterlitz-Thouless quantum phase transition of spin- 1/2 XXZ chain is investigated. Quantum Fisher informations of the whole N sites and the partial N/3 sites are studied. They display very similar behaviors, even though their mathematical formulas are very different from each other. The universally critical exponent of quantum Fisher information is obtained as beta=0.47, which is consistent with the results obtained by the renormalized concurrence or discord. We also discuss the relationship between quantum Fisher information and entanglement