论文标题
部分可观测时空混沌系统的无模型预测
Open Wilson chain numerical renormalization group approach to Green's functions
论文作者
论文摘要
通过将Wilson的数值重归其化基团与修改的Bloch-Redfield方法相结合，我们能够消除标准数值重新分配组算法所需的量子杂质光谱函数的Lehmann表示的人为扩大。我们的方法基于原始量子杂质模型中连续耦合函数的精确再现。它通过与额外的水库耦合来增强威尔逊链的每个连锁店。这个开放的威尔逊链是由连续的分数扩展构建的，在Bloch-Redfield方法的背景下，耦合函数将以二阶处理。由此产生的Bloch-Redfield张量的特征值产生了数值重新归一化的激发的有限寿命，从而导致光谱函数的自然扩展。我们将这种方法与Z平平和自我能源相关部分的分析精确表达相结合，以在不存在和存在外部磁场的情况下获得原始连续模型的光谱函数的准确表示。
By combining Wilson's numerical renormalization group with a modified Bloch-Redfield approach we are able to eliminate the artificial broadening of the Lehmann representation of quantum impurity spectral functions required by the standard numerical renormalization group algorithm. Our approach is based on the exact reproduction of the continuous coupling function in the original quantum impurity model. It augments each chain site of the Wilson chain by a coupling to an additional reservoir. This open Wilson chain is constructed by a continuous fraction expansion and the coupling function is treated in second order in the context of the Bloch-Redfield approach. The eigenvalues of the resulting Bloch-Redfield tensor generate a finite life time of the numerical renormalization group excitations that leads to a natural broadening of the spectral functions. We combine this approach with z-averaging and an analytical exact expression for the correlation part of the self-energy to obtain an accurate representation of the spectral function of the original continuum model in the absence and presence of an external magnetic field.
