论文标题
Kugel-Khomskii模型中外部磁场的量子纠缠，局部指标和效果
Quantum entanglement, local indicators and effect of external fields in the Kugel-Khomskii model
论文作者
论文摘要
使用精确的对角技术，我们确定了具有不同类型的Intersubsystem交换项的两旋（Kugel-Khomskii）模型所描述的有限链的能量光谱和波函数。发现的解决方案提供了解决此类模型固有的量子纠缠问题的可能性。我们将主要重点放在被视为纠缠的足够数值度量的同时计算的计算上。我们还分析了被认为是纠缠局部指标的两点相关函数的行为。我们构建涉及非零纠缠区域的模型的相图。外部场的明显效果与纠缠区域的两个自旋变量结合在一起，可以根据模型的参数增强和削弱纠缠。
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 found solutions provide a possibility to address the problem of quantum entanglement inherent to 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 as 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 on the regions with entanglement, could both enhance and weaken the entanglement depending on the parameters of the models.
