Faculty of Computing, University of Latvia, Riga LV-1586, Latvia.
Phys Rev Lett. 2010 May 7;104(18):186805. doi: 10.1103/PhysRevLett.104.186805.
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.
动态量子点可以通过时变静电势形成，例如在栅极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种用可控数量的电子初始化量子点的方案。它基于电子势能的快速增加和与源极的同时解耦。通过求解单个电子逃逸事件的随机级联的主方程，得到最终捕获电子数量的完整概率分布。我们推导出一个显式拟合公式，从周期性驱动器件中测量的平均电流中提取衰减率比序列。这提供了一个特定于器件的指纹，允许我们比较不同的架构，并从低精度测量中预测初始化精度的上限。
