Systematic method for studying single-electron transistors

Abstract

We present a thorough classification of the electronic transport patterns of single-electron transistors (SETs) using a two-letter notation, based on the symmetry properties of SETs and a nondimensionalization procedure. We find five unique symmetry types of SETs: one symmetric and four asymmetric. For these types and the corresponding dimensionless transistor parameter sets, denoted by the two-letter scheme, we calculate and compare current–voltage curves, modulation curves, charge stability diagrams, and the average and standard deviation of the number of excess electrons on the transistor island. The simulation is performed using the mean of the recurrent solution method for the system of kinetic equations for the charge probability distribution function. On the basis of the simulation results, we analyze the properties of asymmetric SETs. We also consider the effect of asymmetry in the transistor bias voltage and show that this effect can be compensated by renormalization of the left and right junction capacitances. In addition, we propose a measurement technique that can be used to determine the voltage bias asymmetry ratio in real experiments. Finally, using the Bardeen approximation for the tunnel matrix element and the parallel-plate capacitor approximation, we estimate the geometric features of the tunnel junctions.