Investigations of local electronic transport in InAs nanowires by scanning gate microscopy at helium temperatures

TL;DR

This study uses scanning gate microscopy at helium temperatures to explore local electronic transport in InAs nanowires, revealing effects like Coulomb blockade, tunneling barriers, and standing wave phenomena.

Contribution

It provides detailed experimental insights into the local electronic behavior of InAs nanowires, including effects of defects, barriers, and carrier concentration variations.

Findings

Observation of Coulomb blockade effects.

Identification of quasi-periodic standing waves.

Impact of contact opacity on transport regimes.

Abstract

In the current paper a set of experiments dedicated to investigations of local electronic transport in undoped InAs nanowires at helium temperatures in the presence of a charged atomic-force microscope tip is presented. Both nanowires without defects and with internal tunneling barriers were studied. The measurements were performed at various carrier concentrations in the systems and opacity of contact-to-wire interfaces. The regime of Coulomb blockade is investigated in detail including negative differential conductivity of the whole system. The situation with open contacts with one tunneling barrier and undivided wire is also addressed. Special attention is devoted to recently observed quasi-periodic standing waves.