Multitip scanning gate microscopy for ballistic transport studies in systems with two-dimensional electron gas

TL;DR

This paper explores multi-tip scanning gate microscopy for two-dimensional electron gas systems, demonstrating how it can be used to analyze ballistic transport properties, detect defects, and tune system resonances.

Contribution

It introduces novel multi-tip techniques for conductance mapping and provides procedures for extracting and manipulating ballistic transport characteristics.

Findings

Multi-tip methods can determine the Fermi wavelength.

Detection of potential defects is feasible with multi-tip SGM.

Resonant conditions enable stable local density of states mapping.

Abstract

We consider conductance mapping of systems based on the two-dimensional electron gas with scanning gate microscopy using two and more tips of the atomic force microscope. The paper contains results of numerical simulations for a model tip potential with a proposal of a few procedures for extraction and manipulation the ballistic transport properties. In particular, we demonstrate that the multi-tip techniques can be used for readout of the Fermi wavelength, detection of potential defects, filtering specific transverse modes, tuning the system into resonant conditions under which a stable map of a local density of states can be extracted from conductance maps using a third tip.