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

A. A. Zhukov, Ch. Volk, A. Winden, H. Hardtdegen, Th. Schaepers

Published 2013-09-10, updated 2013-09-14Version 2

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.