arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1801.04733cond-mat.mes-hall
收藏

量子点泵浦产生量子化电流的数值模拟

Numerical Simulation of Quantized Current Generated by a Quantum Dot Pump

Ye-Hwan Ahn, Yunchul Chung

摘要:

数值计算了量子点泵浦产生的量子化电流。数值模拟是通过将时变势场分解为多个时间间隔很短的静态势场,并利用与时间无关的薛定谔方程计算电子俘获和泵浦速率来实现的。模拟结果与实验结果定性吻合较好。计算的二维泵浦电流图和平台宽度对调制栅电压的依赖关系与实验结果吻合较好。从模拟结果,它是解释如何反向隧穿过程影响的电流平台的准确性定量。计算了抽运电子的能量分布,并可通过实验测量。最后发现,增加入射栅宽度可以提高泵浦电流的精度,这对实现量子电流标准具有重要意义。

英文摘要:

The quantized current generated by a quantum dot pump is calculated numerically. The numerical simulation is done by dividing the time varying potential into many static potentials with a short time interval and calculating the electron capture and pumping rate with the time independent Schrodinger equation. The simulation results show good agreement with reported experimental results qualitatively. The calculated 2D pump current map and the plateau width dependence on the modulation gate voltage show good agreement with the experimental results. From the simulation results, it is explained how the back-tunneling process affects the accuracy of the current plateaus quantitatively. Also, the energy distribution of the pumped electron is calculated, which can be measured experimentally. Finally, it is found that the pump current accuracy can be enhanced by increasing the entrance gate width, which is important to realize the quantum current standard.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑