Memory loss and Auger processes in a many-body theory of charge transfer.
Memory loss and Auger processes in a many-body theory of charge transfer.
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电荷转移多体理论中的记忆丧失和俄歇过程。
DOI：
10.1103/physrevb.53.13340
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Marston
中科院分区：
文献类型：
--
作者：
Onufriev;Marston
高温碱原子和金属散射表面之间的电荷转移是多体相互作用的实验和理论领域。为了模拟新的面，我们使用了广义的时变牛顿-安德森哈密顿量，其中包括电子自旋、具有像移能级的多原子轨道、原子内库仑排斥和共振交换。变分电子多体波函数解决了动力学问题。波函数由具有零或一个粒子空穴对的扇区组成，并且通过包含中性原子和电子空穴对的振幅而超越了先前的工作。具有一个以上粒子-空穴对的高阶扇区被$1/N$的幂抑制；因此，波函数ansatz等价于$1/N$展开。运动方程是数值积分，无需进一步逼近。该解决方案显示了改进的记忆损失-最终电荷状态与初始电荷状态无关-符合理论和实验预期。通过对熵产生的分析，加深了对这一现象的理解。通过研究独立粒子近似，并通过检查希尔伯特空间的不同部分在熵产生中所起的作用，我们得出了多体解中发生记忆丧失的充分必要条件。作为理论的进一步检验，我们重现了实验观察到的从不同初始条件开始的中间功函数中激发中性Li（2p）占用的峰值。接下来，我们通过在多体哈密顿量中加入两体相互作用项来包括俄歇过程。考虑了几种类型的螺旋钻过程，这些过程被证明会影响低状态的最终占有率
Charge transfer between hyperthermal alkali atoms and metallic scattering surfaces is an experimental and theoretical arena for many-body interactions. To model new facets, we use a generalized time-dependent Newns-Anderson Hamiltonian which includes electron spin, multiple atomic orbitals with image shifted levels, intra-atomic Coulomb repulsion, and resonant exchange. A variational electronic many-body wave function solves the dynamical problem. The wave function consists of sectors with either zero or one particle-hole pair and goes beyond earlier work through the inclusion of amplitudes for a neutral atom plus an electron-hole pair. Higher order sectors with more than one particle-hole pair are suppressed by powers of $1/N$; hence the wave function ansatz is equivalent to a $1/N$ expansion. The equations of motion are integrated numerically without further approximation. The solution shows improved loss-of-memory -- the final charge state is independent of the initial one -- in agreement with theoretical and experimental expectations. Understanding of this phenomenon is deepened through an analysis of entropy production. By studying the independent-particle approximation, and by examining the role played by different sectors of the Hilbert space in entropy production, we arrive at necessary and sufficient conditions for loss-of-memory to occur in the many-body solution. As further tests of the theory, we reproduce the experimentally observed peak in the excited neutral Li(2p) occupancy at intermediate work functions starting from different initial conditions. Next, we include Auger processes by adding two-body interaction terms to the many-body Hamiltonian. Several types of Auger processes are considered, and these are shown to affect the final state occupancies at low