Quantum renormalization of entanglement in an antisymmetric anisotropic and bond-alternating spin system

TL;DR

This paper investigates how quantum renormalization affects entanglement and phase transitions in an anisotropic, bond-alternating spin chain, revealing critical behavior and entanglement enhancement due to quantum fluctuations.

Contribution

It applies quantum renormalization group techniques to analyze entanglement and criticality in a complex spin system with antisymmetric anisotropy and alternating interactions, providing new insights into quantum phase transitions.

Findings

Discontinuity in the second derivative of energy indicates phase transitions.

Entanglement entropy diverges at critical points after renormalization.

Antisymmetric anisotropy and alternating interactions enhance entanglement.

Abstract

The quantum renormalization group method is applied to study the quantum criticality and entanglement entropy of the ground state of the Ising chain in the presence of antisymmetric anisotropic couplings and alternating exchange interactions. The quantum phase transitions can be characterized by the discontinuity in the second derivative of the energy of renormalized ground state. The phase diagram is obtained by the critical boundary line. The first derivative of entanglement entropy also diverges at the same critical points after enough iterations of the renormalization of coupling constants. The antisymmetric anisotropy and alternating interaction can enhance the renormalized entanglement via the creation of quantum fluctuations. The scaling behavior of the derivative of the entropy around the critical points manifest the logarithm dependence on the size of the spin system.