Universal Decay Cascade Model for Dynamic Quantum Dot Initialization
Universal Decay Cascade Model for Dynamic Quantum Dot Initialization
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DOI：
10.1103/physrevlett.104.186805
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发表时间：
2010-05-07
影响因子：
8.6
通讯作者：
Kaestner, Bernd
中科院分区：
文献类型：
--
作者：
Kashcheyevs, Vyacheslavs;Kaestner, Bernd
动态量子点可以由时间相关的静电电位形成，例如在门或表面声波驱动的电子泵中。在这项工作中，我们提出并量化了一个初始化量子点的方案，该方案具有可控的电子数量。它是基于电子势能的快速增加和同时从源引线解耦。通过求解单电子逃逸事件随机级联的主方程，得到了最终捕获电子数的全概率分布。我们推导了一个显式拟合公式，从周期性驱动器件的平均电流测量中提取衰减率比序列。这提供了一个特定于设备的指纹，允许我们比较不同的体系结构，并从低精度测量中预测初始化精度的上限。
Dynamic quantum dots can be formed by time-dependent electrostatic potentials, such as in gate- or surface-acoustic-wave-driven electron pumps. In this work we propose and quantify a scheme to initialize quantum dots with a controllable number of electrons. It is based on a rapid increase of the electron potential energy and simultaneous decoupling from the source lead. The full probability distribution for the final number of captured electrons is obtained by solving a master equation for stochastic cascade of single electron escape events. We derive an explicit fitting formula to extract the sequence of decay rate ratios from the measurements of averaged current in a periodically driven device. This provides a device-specific fingerprint which allows us to compare different architectures, and predict the upper limits of initialization accuracy from low precision measurements.