Simulation of electronic properties of a quantum dot in transistor geometry at varying temperatures

Abstract

Electrical conduction is the ow of electron due to a force applied by an electric eld. In bulk material, conduction process obeys Ohm's law. The law states that current is proportional to applied voltage. But nano-sized objects behave di erently. At these range quantum e ects modify the electronic conduction properties and exhibit a staircase-like conduction. This is also known as Coulomb staircase. In our work, electronic properties of a quantum dot was investigated in transistor geometry. As a device a simpli ed Single Electron Transistors (SET's) model has been considered, which is made of a quantum dot connected through two tunneling junctions to a source and a drain electrode, and capacitively coupled to a gate electrode. Single-Electron Transistors are often discussed as elements of nanometer scale electronic circuits because they can be made very small and they can detect the motion of individual electrons. A Python program has been developed based on rate equations and IvsV characteristic graph as a function of temperature has been obtained using numerical calculation. Then radius of the quantum dot has been determined at a temperature when the QD is shifted away form quantum regime and falls into classical regime.