Spin-Orbital Entanglement and Phase Diagram of Spin-orbital Chain with $SU(2) \times SU(2)$ Symmetry

TL;DR

This paper investigates spin-orbital entanglement in a quantum chain with $SU(2) imes SU(2)$ symmetry, using von Neumann entropy to map out a complex phase diagram and identify quantum phase transitions.

Contribution

It introduces a method to quantify spin-orbital entanglement and efficiently determine phase boundaries in systems with multiple correlated degrees of freedom.

Findings

Identified multiple quantum phase transitions via entropy analysis

Mapped a detailed phase diagram of the spin-orbital chain

Demonstrated an effective approach for complex correlated systems

Abstract

Spin-orbital entanglement in quantum spin-orbital systems is quantified by a reduced von Neumann entropy, and is calculated for the ground state of a coupled spin-orbital chain with $SU(2)\times SU(2)$ symmetry. By analyzing the discontinuity and local extreme of the reduced entropy as functions of the model parameters, we deduce a rich phase diagram to describe the quantum phase transitions in the model. Our approach provides an efficient and powerful method to identify phase boundaries in a system with complex correlation between multiply degrees of freedom.