Influence of the surface charge on the operation of ballistic T-branch junctions: a self-consistent model for Monte Carlo simulations

Abstract

We analyse the influence of the surface charge on the operation of ballistic T-branch junctions by means of a semi-classical 2D Monte Carlo simulator. We propose a new self-consistent model in which the local value of the surface charge is dynamically adjusted depending on the surrounding carrier density. The well-known parabolic behaviour of the central branch potential VC when biasing right and left branches in a push–pull fashion is found to be much influenced by the value of the surface charge in both the horizontal and vertical branches. With the help of experimental measurements performed in real devices, the influence of the width of the central branch on the values of VC and its relation to surface charge effects are also studied.