Signatures of spin-orbit interaction in transport properties of finite carbon nanotubes in a parallel magnetic field

TL;DR

This paper investigates how spin-orbit interaction and curvature effects influence the transport properties of finite carbon nanotubes in a parallel magnetic field, revealing phenomena like current suppression and tunable spin-polarized currents.

Contribution

It demonstrates the impact of spin-orbit coupling and chirality on transport, including magnetic-field-induced current suppression and reversible spin polarization in finite nanotubes.

Findings

Current suppression occurs at specific magnetic fields depending on chirality and length.

Reversible spin-polarized currents can be achieved by tuning the magnetic field.

Transport properties are significantly affected by spin-orbit and curvature effects.

Abstract

The transport properties of finite nanotubes placed in a magnetic field parallel to their axes are investigated. Upon including spin-orbit coupling and curvature effects, two main phenomena are analyzed which crucially depend on the tube's chirality: i) Finite carbon nanotubes in a parallel magnetic field may present a suppression of current due to the localization at the edges of otherwise conducting states. This phenomenon occurs due to the magnetic-field dependent open boundary conditions obeyed by the carbon nanotube's wave functions. The transport is fully suppressed above threshold values of the magnetic field which depend on the nanotube chirality, length and on the spin-orbit coupling. ii) Reversible spin polarized currents can be obtained upon tuning the magnetic field, exploiting the curvature-induced spin-orbit splitting.