Simulations of Relaxation Processes for Non-Equilibrium Electron Distributions in Two-Dimensional Tunnel Junction Arrays

Relaxation processes for non-equilibrium electron distributions in two-dimensional ultrasmall tunnel junction arrays (2D-TJAs) have been studied using a Monte Carlo simulation. Many electrons initially placed in the central island diffuse outward due to single-electron tunneling. When we focus on the number of electrons in square shells dividing the 2D-TJA, the number of electrons strongly fluctuates in time to form electron bunching peaks, and the peaks are propagated to outer shells as a wave. This result indicates a self-organization of electrons in non-equilibrium TJAs, suggesting the possibility of applications based on a new algorithm.