Competition between magnetic field dependent band structure and coherent backscattering in multiwall carbon nanotubes

TL;DR

This study investigates how magnetic field-dependent band structure and quantum interference effects compete in determining the magnetotransport properties of large-diameter multiwall carbon nanotubes, revealing insights into their electronic behavior.

Contribution

It demonstrates the interplay between bandstructure effects and quantum interference in multiwall carbon nanotubes through combined experimental and numerical analysis.

Findings

Magnetoconductance oscillations depend on Fermi level shifts and magnetic field orientation.

Qualitative agreement between experimental results and numerical band structure calculations.

Identification of contributions from different Aharonov-Bohm phases.

Abstract

Magnetotransport measurements in large diameter multiwall carbon nanotubes (20-40 nm) demonstrate the competition of a magnetic-field dependent bandstructure and Altshuler-Aronov-Spivak oscillations. By means of an efficient capacitive coupling to a backgate electrode, the magnetoconductance oscillations are explored as a function of Fermi level shift. Changing the magnetic field orientation with respect to the tube axis and by ensemble averaging, allows to identify the contributions of different Aharonov-Bohm phases. The results are in qualitative agreement with numerical calculations of the band structure and the conductance.