论文标题
在不均匀磁场中的二维耗散旋转系统的热状态下的纠缠稳健性和自旋松弛
Entanglement robustness and spin relaxation in thermal states of two-dimensional dissipative spin system in an inhomogeneous magnetic field
论文作者
论文摘要
我们考虑有限的二维海森堡三角形旋转晶格，在不同程度的各向异性上与耗散性的lindblad环境耦合，在有限温度下遵守born-markovian的约束。我们展示了如何将不均匀磁场应用于系统中如何显着影响系统渐近稳态中自旋之间的纠缠分布和性质。特别是，发现在完全各向异性（ISING）系统中，应用具有向内（增长）梯度向中心自旋的不均匀场（增长）梯度朝向中心自旋，及其对热耗散衰减效应的鲁棒性，而所有超越最近的邻居纠缠完全消失了。将相同的字段应用于部分各向异性（XYZ）系统，不仅可以增强最近的邻居纠缠及其稳健性，而且还可以增强最近的邻居。然而，该领域的不均匀性对各向同性（XXX）系统中纠缠的渐近行为没有影响，该系统在任何系统配置下都消失了。此外，相同的不均匀场对旋转动力学也表现出最大的影响力。尽管在各向同性系统中，旋转放松至可分离的（分离的）稳态，所有旋转都达到了共同的旋转状态，而不管野外不均匀性，但完全各向异性系统的稳态旋转取决于其在晶格中的位置，都可以达到不同的杰出旋转状态。但是，在XYZ系统中，尽管各向异性较低，但自旋状态变得更加区别，伴随着整个系统的远距离量子相关性，这是系统各向异性和田间不良性的这种结合下发生关键行为的迹象。
We consider a finite two-dimensional Heisenberg triangular spin lattice at different degrees of anisotropy coupled to a dissipative Lindblad environment obeying the Born-Markovian constrain at finite temperature. We show how applying an inhomogeneous magnetic field to the system may significantly affect the entanglement distribution and properties among the spins in the asymptotic steady state of the system. Particularly, applying an inhomogeneous field with an inward (growing) gradient toward the central spin is found to considerably enhance the nearest neighbor entanglement and its robustness to the thermal dissipative decay effect in the completely anisotropic (Ising) system, whereas all the beyond nearest neighbor entanglements vanish entirely. Applying the same field to a partially anisotropic (XYZ) system, does not only enhance the nearest neighbor entanglements and their robustness but also all the beyond nearest neighbor ones. Nevertheless, the inhomogeneity of the field shows no effect on the asymptotic behavior of the entanglement in the isotropic (XXX) system, which vanishes under any system configuration. Moreover, the same inhomogeneous field exhibits the most influential impact, compared with the other ones, on the the spin dynamics as well. Although in the isotropic system the spins relax to a separable (disentangled) steady state with all the spins reaching a common spin state regardless of the field inhomogeneity, the spins in the steady state of the completely anisotropic system reach different distinguished spin states depending on their positions in the lattice. However, in the XYZ system, though the anisotropy is lower, the spin states become even more distinguished, accompanying the long range quantum correlation across the system, which is a sign of a critical behavior taking place at this combination of system anisotropy and field inhomogeneity.
