Adaptive Simulation for Single-Electron Devices

Single-electron devices have drawn much attention in the last two decades. They have been widely used for device research and also show promise as a potential alternative to complementary metal-oxide- semiconductor circuits due to their ultra low power dissipation. Three techniques have been used for single-electron device modeling in the past, including Monte Carlo simulation, master equation, and SPICE modeling. Among these, Monte Carlo method provides accuracy, but lacks the time efficiency required for large scale simulation. In this work, we introduce an adaptive multi-scale approach to single- electron device simulation using Monte Carlo method as basis, which significantly improves time efficiency while maintaining accuracy. We have shown it is possible to reduce simulation time up to 40 times and maintain an average error of 3.3% compared to non-adaptive Monte Carlo method. Going beyond simplistic approximations, we have modeled important secondary effects including cotunneling and Cooper pair tunneling, which are critical for device research.