【摘要】 提出了一个建立在子动力学运动方程上的非平衡统计系综体系,该体系可以通过对吉布斯系综体系进行一个相似变换得到。由此可以得到子动力学系综的投影密度算符。从某种意义上说该体系可以看作一般的平衡态或非平衡态量子正则系综体系:1)如果相似算符是么正的,所得的新公式则就是原来正则系综公式的等效式;2)如果算符不是么正的,新公式则是原公式的扩展或延伸,代表了非平衡量子正则系综,且反映了系统的不可逆性;3)如果通过一些近似,相似算符可以被引入,例如马尔科夫/非马尔科夫近似等,则新的公式也可以显示一些系统不可逆的性质,这些性质不可能从平衡态正则系综获得。研究了一个描述为安德逊模型的量子强关联网络的模型来作为此理论的应用。同时还引进了相应的格林函数,发现系统的复数形式的熵值与网络节点上的局域磁矩有关,而熵的虚部则反映着熵的演化率。更多还原

【Abstract】 In this work,we present a nonequilibrium ensemble formalism based on the subdynamic kine-tic equation.The constructing procedure is to take a similarity transformation to Gibbsian ensemble formalism.This allows one to obtain subdynamic ensemble formalism for projected density operator.This formalism can be considered as a generalization of the equilibrium quantum canonical ensemble formula in the sense as 1) if the similarity operator is unitary,then the new formula is just an effective representation of the old canonical ensemble formula,2) if the similarity operator is non-unitary,then the new formula is an extension of the old formula,which represents a kind of non-equilibrium quantum canonical ensembles formula and reflects irreversibility of the system,and 3) if the similarity operator can be deduced by some approximations,such as Markovian/non-Markovian approximations,then the new formula can expose some irreversibility characteristics of the system which can not be gained from the equilibrium quantum ensemble formulas.As an application,we study a quantum strongly correlated network described by an Anderson model.A Green function based on this formalism is also introduced.We find the complex entropy of the system to be related to appearance of the local magnetic vectors in the nodes of the network,where the image part of the entropy represents an evolution rate of the entropy.更多还原