We have processed Hall contacts on InAs nanowires grown by molecular beam epitaxy using an electron beam lithography process with an extremely high alignment accuracy. The carrier concentrations determined from the Hall effect measurements on these nanowires are lower by a factor of about 4 in comparison with those measured by the common field-effect technique. The results are used to evaluate quantitatively the charging effect of the interface and surface states.
Magnetotransport measurements at low temperatures have been performed on InAs nanowires grown by In-assisted molecular beam epitaxy. Information on the electron phase coherence is obtained from universal conductance fluctuations measured in a perpendicular magnetic field. By analysis of the universal conductance fluctuations pattern of a series of nanowires of different length, the phase-coherence length could be determined quantitatively. Furthermore, indications of a pronounced flux cancelation effect were found, which is attributed to the topology of the nanowire. Additionally, we present measurements in a parallel configuration between wire and magnetic field. In contrast to previous results on InN and InAs nanowires, we do not find periodic oscillations of the magnetoconductance in this configuration. An explanation of this behavior is suggested in terms of the high density of stacking faults present in our InAs wires.
We investigated the transport properties of GaAs/InAs core/shell nanowires grown by molecular beam epitaxy. Owing to the band alignment between GaAs and InAs, electrons are accumulated in the InAs shell as long as the shell thickness exceeds 12 nm. By performing simulations using a Schrödinger-Poisson solver, it is confirmed that confined states are present in the InAs shell, which are depleted if the shell thickness is below a threshold value. The existence of a tubular-shaped conductor is proved by performing magnetoconductance measurements at low temperatures. Here, flux periodic conductance oscillations are observed which can be attributed to transport in one-dimensional channels based on angular momentum states.
InN nanowires, grown by plasma-enhanced molecular beam epitaxy, were investigated by means of magnetotransport. By performing temperature-dependent transport measurements and current measurements on a large number of nanowires of different dimensions, it is proven that the carrier transport mainly takes place in a tube-like surface electron gas. Measurements on three representative nanowires under an axially oriented magnetic field revealed pronounced magnetoconductance oscillations with a periodicity corresponding to a single magnetic flux quantum. The periodicity is explained by the effect of the magnetic flux penetrating the coherent circular quantum states in the InN nanowires, rather than by Aharonov-Bohm type interferences. The occurrence of the single magnetic flux quantum periodicity is attributed to the magnetic flux dependence of phase-coherent circular states with different angular momentum quantum numbers forming the one-dimensional transport channels. These phase coherent states can exist because of the almost ideal crystalline properties of the InN nanowires prepared by self-assembled growth.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.