Analytical approximations of single-electron device current through non-interacting quantum dot

Abstract

Abstract The electron transport through single electron transistor (SET) consisting of quantum dot (QD) coupled to two metallic electrodes has been studied by employing the non-equilibrium Green function (NEGF) technique. The QD considered in this study has a single energy level and non-interacting electrons. The current-voltage characteristics of QD has been studied by using Meir-Wingreen expression. In this paper, an analytical approximation of Meir-Wingreen formula has been presented with respect to the following conditions: (1) low-temperature limit, (2) finite temperature limit with finite energy | e − e d | k T , (3) finite temperature limit with finite bias Γ e | V | / 2 K T e d , and at high temperatures. Furthermore, the derived analytical formulae are employed to investigate the effect of device parameters (energy level, tunneling rate “level width”, gate voltage, and temperature) on the current-voltage characteristic of SET.