Modeling of Coulomb blockade devices and circuits with random structures

由于库仑阻塞发生在电容非常小的隧道结中，利用这种现象的器件必须具有非常小的结构。因此，当今的实验装置往往具有随机结构。在本研究中，库仑阻塞器件的电路是在绝缘体薄膜上沉积的二维不规则的金属微粒阵列，最近的金属微粒对形成隧道结。由细小的金属颗粒形成的系统，圆点，模型化如下。假设网点系统具有规则的二维网格结构，并通过每个结点的电容和电阻的随机值来考虑随机性。在这些点的上方放置栅电极，并且在栅和点之间形成电容。这些值由COMPUTE中生成的规则随机数设置。在正统理论的基础上，通过一个用于电路模拟的程序，得到了每个隧道结的临界电荷。分析了规则电容和随机电容的不同情况对电特性的影响。

Since Coulomb blockade takes place in tunnel junctions with very small capacitance, devices utilizing this phenomenon must have very small structures. Accordingly, experimental devices of nowadays often have random structures. In this study Coulomb blockade device circuits with two-dimensional irregular array of fine metallic particles deposited on an insulator film.The nearest neighbor fine metallic particles pair forms a tunnel junction. A system which is formed from the fine metallic particles, dots, is modelled as follows. The system of the dots is assumed to have regular two-dimensional grid structures and the randomness is taken into account by the random values of capacitance and resistance of each junction. Above the dots a gate electrode is placed, and capacitances are formed between the gate and the dots. These values are set by regular random numbers generated in compute. Critical charge for each tunnel junction is obtained by a program to use in the circuit simulation based on the orthodox theory. The influences of the difference between the cases of regular and random capacitances on the electrical characteristics are esamined.