Accessing nanotube bands via crossed electric and magnetic fields

TL;DR

This paper explores how crossed electric and magnetic fields influence conduction electrons in armchair carbon nanotubes, revealing asymmetric dispersion, spin-band-charge separation, and tunable quantum states with potential experimental applications.

Contribution

It introduces a novel analysis of field-induced effects on nanotube electronic properties, including asymmetric dispersion and quantum state control, not previously detailed in the literature.

Findings

Fields induce asymmetric electron dispersion in nanotubes.

Prediction of spin-band-charge separation due to fields.

Fields enable tuning of quantum states in nanotube quantum dots.

Abstract

We investigate the properties of conduction electrons in single-walled armchair carbon nanotubes in the presence of mutually orthogonal electric and magnetic fields transverse to the tube's axis. We find that the fields give rise to an asymmetric dispersion in the right- and left-moving electrons along the tube as well as a band-dependent interaction. We predict that such a nanotube system would exhibit spin-band-charge separation and a band-dependant tunneling density of states. We show that in the quantum dot limit, the fields serve to completely tune the quantum states of electrons added to the nanotube. For each of the predicted effects, we provide examples and estimates that are relevant to experiment.