论文标题
在费米金耗散环境中的Landau-Zener过渡
Landau-Zener transitions in a fermionic dissipative environment
论文作者
论文摘要
我们在费米文化耗散环境中研究Landau-Zener转变，在该环境中，将两级（上下状态）系统耦合到两个金属导线，并在零温度下保持不同的化学电位。系统的动力学通过迭代在数值上的影响功能路径积分方法进行了模拟。在纯净的Landau-Zener问题中，概率是两种过渡（从状态到向下到向上）的概率是对称的。但是，这种对称性通过将系统耦合到浴室而被破坏。另外，在两种过渡中，都存在过渡概率对扫描速度的非单调依赖性。同时，过渡概率对系统轴耦合强度的非单调依赖性仅在其中一个显示。与自旋玻色子模型一样，这些现象可以通过简单的现象学模型来解释。
We study Landau-Zener transitions in a fermionic dissipative environment where a two-level (up and down states) system is coupled to two metallic leads kept with different chemical potentials at zero temperature. The dynamics of the system is simulated by an iterative numerically exact influence functional path integral method. In the pure Landau-Zener problem, two kinds of transition (from up to down state and from down to up state) probability are symmetric. However, this symmetry is destroyed by coupling the system to the bath. In addition, in both kinds of transitions, there exists a nonmonotonic dependence of the transition probability on the sweep velocity; meanwhile nonmonotonic dependence of the transition probability on the system-bath coupling strength is only shown in one of them. As in the spin-boson model, these phenomena can be explained by a simple phenomenological model.
