Transport and dephasing in a quantum dot: Multiply connected graph model
Transport and dephasing in a quantum dot: Multiply connected graph model
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量子点中的传输和移相：多重连通图模型
DOI：
10.1002/andp.201100258
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发表时间：
2012
影响因子：
2.4
通讯作者：
I. V. Lerner
中科院分区：
文献类型：
--
作者：
M. Treiber;O. M. Yevtushenko;F. Marquardt;J. von Delft;I. V. Lerner
利用图中的扩散理论，我们提出了一个模型来研究通过扩散量子点的介观输运。该图由三个准1D区域组成：描述点的中心区域，以及连接到电极导线的两个相同的左右线，其模拟真实的系统的触点。我们找到了这个图的扩散方程的精确解，并评估了包括量子校正在内的电导。我们的模型是对描述量子点的RMT模型的补充。首先，它再现了零温度下的普适极限。但与RMT模型相比，它的主要优点是允许考虑有限温度下相互作用引起的退相。此外，从开放到几乎封闭的量子点之间的交叉以及不同的退相机制之间的交叉可以在一个框架内描述。我们提出的结果的温度依赖性的弱局域化校正的电导的实验相关的参数范围内，并讨论了观察难以捉摸的0 D-制度的退相在不同的介观系统的可能性。
Using the theory of diffusion in graphs, we propose a model to study mesoscopic transport through a diffusive quantum dot. The graph consists of three quasi‐1D regions: a central region describing the dot, and two identical left‐ and right‐ wires connected to leads, which mimic contacts of a real system. We find the exact solution of the diffusion equation for this graph and evaluate the conductance including quantum corrections. Our model is complementary to the RMT‐models describing quantum dots. Firstly, it reproduces the universal limit at zero temperature. But the main advantage compared to RMT‐models is that it allows one to take into account interaction‐induced dephasing at finite temperatures. Besides, the crossovers from open to almost closed quantum dots and between different regimes of dephasing can be described within a single framework. We present results for the temperature dependence of the weak localization correction to the conductance for the experimentally relevant parameter range and discuss the possibility to observe the elusive 0D‐regime of dephasing in different mesoscopic systems.