两比特海森堡自旋链体系中几何量子失协在非马尔可夫环境下的演化

Evolution of Geometric Quantum Discord of Two-Bit Heisenberg Spin Chain System in Non-Markovian Environment

利用量子态扩散方法,研究了在非马尔可夫环境下海森堡XXZ自旋模型中几何量子失协(GQD)的演化特性。分析了环境关联参数γ、xy平面上的耦合常数J_(xy)、z方向上的耦合常数J_(z)、外加磁场B以及DzyaloshinskiiMoriya(DM)相互作用对GQD动力学演化特性的影响。结果表明:γ越短,即环境的非马尔可夫效应越明显,越有利于有效提高系统的GQD;选取的初始态不同,J_(xy)和J_(z)对GQD起到的作用也不同;在非马尔可夫环境下,适当地增大B可提高GQD,而DM相互作用的引入会导致GQD衰减振荡。值得一提的是:可以从无纠缠初态系统有效地诱导出GQD。

The evolution properties of geometric quantum discord(GQD)of the Heisenberg XXZ spin model in a nonMarkovian environment are studied using the quantum state diffusion method.The influences of environmental correlation parametersγ,coupling constants in the xy plane J_(xy),coupling constants in the z direction J_(z),applied magnetic field B and DzyaloshinskiiMoriya(DM)interactions on the GQD dynamics are analyzed.The results show that the shorter theγis,the more obvious the nonMarkovian characteristics of the environment are,the better it is to effectively improve the GQD;J_(xy) and J_(z) have different effects on the GQD when different initial states are selected;in the nonMarkovian environment,increasing the magnetic field B can improve the GQD,while the DM interaction will lead to decaying oscillations of the GQD.It is worth mentioning that the GQD can be effectively induced from the entanglementfree initial state system.