Electronic spectral shift of oxygen-filled (6,6) carbon nanotubes

TL;DR

This paper theoretically investigates how encapsulating oxygen molecules in (6,6) carbon nanotubes affects their electronic states, revealing a length-dependent spectral gap formation influenced by magnetic interactions.

Contribution

It introduces a theoretical model showing oxygen filling induces a magnetic field that modulates electronic states and causes a length-dependent spectral gap in armchair nanotubes.

Findings

Spectral gap appears near the Fermi energy due to oxygen filling.

Gap formation depends on nanotube length being a multiple of three.

Magnetic coupling of oxygen influences electronic eigenenergies.

Abstract

Electronic state modulation of the armchair (6,6) carbon nanotubes filled with a linear assembly of oxygen molecules is addressed theoretically. Ferromagnetic coupling of encapsulated oxygen produces a magnetic field with cylindrical symmetry, which deviates the electron's eigenenergies from those prior to the oxygen absorption. An intriguing spectral gap arises near the Fermi energy, at which the gap formation is allowed only when the tube length equals to a multiple of three in units of carbon hexagon. A possible means to detect the selective gap formation is discussed.