Quantum entanglement, local indicators, and the effect of external fields in the Kugel-Khomskii model

Article

关键词: ELEMENTARY EXCITATIONS;    PYTHON FRAMEWORK;    ORBITAL PHYSICS;    DYNAMICS;    QUTIP;   

DOI  :  10.1103/PhysRevB.102.155125

来源: SCIE

【 摘 要 】

Using the exact diagonalization technique, we determine the energy spectrum and wave functions for finite chains described by the two-spin (Kugel-Khomskii) model with different types of intersubsystem exchange terms. The obtained solutions provide the possibility to address the problem of quantum entanglement inherent in this class of models. We put the main emphasis on the calculations of the concurrence treated as an adequate numerical measure of the entanglement. We also analyze the behavior of two-site correlation functions considered a local indicator of entanglement. We construct the phase diagrams of the models involving the regions of nonzero entanglement. The pronounced effect of external fields, conjugated to both spin variables in the regions with entanglement, could both enhance and weaken the entanglement depending on the parameters of the models.

【 授权许可】

Free