The electronic transport of top subband and disordered sea in InAs nanowire in presence of a mobile gate

TL;DR

This study investigates how a mobile gate affects electronic transport in InAs nanowires, revealing detailed behavior of subband electrons and introducing a new method to detect subband occupation.

Contribution

It presents a novel approach using a charged AFM tip as a mobile gate to study subband and disordered sea electrons in InAs nanowires, including a new detection method for subband occupation.

Findings

Quasiperiodic oscillations depend on electron concentration

Tip-to-sample distance influences local electron control

New method enables evaluation of electrons in the conductive band

Abstract

We performed measurements at helium temperatures of the electronic transport in an InAs quantum wire ($R_{wire} \sim 30$\,k$\Omega$) in the presence of a charged tip of an atomic force microscope serving as a mobile gate. The period and the amplitude of the observed quasiperiodic oscillations are investigated in detail as a function of electron concentration in the linear and non-linear regime. We demonstrate the influence of the tip-to-sample distance on the ability to locally affect the top subband electrons as well as the electrons in the disordered sea. Furthermore, we introduce a new method of detection of the subband occupation in an InAs wire, which allows us to evaluate the number of the electrons in the conductive band of the wire.