单电子晶体管探针的电荷检测机制（英文）

Charge Detection Mechanism of the Single Electron Transistor Probe

单电子晶体管(SET)具有极高的电荷灵敏度,是一种超灵敏电荷计。在先前工作的基础上,首先建立了电荷检测的电路模型,该SET扫描探针系统将SET器件集成制备在探针针尖上。然后利用从已制备的SET探针系统中提取的器件参数,模拟研究了该探针系统对直流偏置的量子点(QD)进行电荷检测的过程,分析了探针系统的耦合系数、电压灵敏度及空间分辨率等性能参数。模拟结果表明,随着探测距离的增加,探针的电导响应减弱。该SET探针系统的电压灵敏度高达10^(-6) V/Hz^(1/2)、空间分辨率大于100 nm。通过模拟,最终获得了该探针系统的量子点的二维电势分布图。

The single electron transistor(SET)is known to be an extremely sensitive electrometer owing to its high charge sensitivity.Firstly,the circuit model for sensing charge based on an SET probe system was built on the basis of previous studies,and the SET scanning probe system was developed with an SET integrated on the probe tip.Then,the device parameters were extracted from the fabricated SET probe system,and the simulation research of the sensing charge process for a DC-biased quantum dot(QD)with the probe system was carried out.Besides,the performance parameters such as the coupling coefficient,voltage sensitivity and spatial resolution of the probe system were analyzed.The simulation results indicate that the conductance response of the probe decreases with the increase of the sensing distance.Besides,a voltage sensitivity as high as 10-6V/Hz1/2 and a spatial resolution better than 100 nm can be achieved for the SET probe system.Finally,a two-dimension potential distribution image of the QD for the probe system was obtained by the simulation.