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.

中文翻译：

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在铁离子耗散环境中的Landau-Zener转变

我们研究了费米离子耗散环境中的Landau-Zener跃迁，在该环境中，两级（上下状态）系统与零温度下保持不同化学势的两条金属引线耦合。通过迭代的数值精确影响函数路径积分方法模拟系统的动力学。在纯Landau-Zener问题中，两种过渡（从上到下状态和从下到上状态）的概率是对称的。然而，通过将系统耦合到浴槽，这种对称性被破坏了。另外，在两种过渡中，过渡概率对扫掠速度都具有非单调的依赖性。同时，仅在其中之一中示出了跃迁概率对系统-浴耦合强度的非单调依赖性。和自旋玻色子模型一样