Quantum walk transport properties on graphene structures

TL;DR

This paper uses numerical quantum walk simulations on graphene and nanotube structures to analyze their transport properties, revealing that nanotube geometry significantly influences quantum transport efficiency.

Contribution

It introduces a novel numerical approach to study quantum walks on graphene-based structures, highlighting the impact of nanotube geometry on transport efficiency.

Findings

Nanotube structures outperform cycles of similar size in quantum transport.

Zig-zag nanotubes exhibit faster transport than armchair nanotubes.

Transport efficiency depends on the symmetry and structure of the nanotubes.

Abstract

We present numerical studies of quantum walks on \C60 and related graphene structures, to investigate their transport properties. Also known as a \emph{honeycomb lattice}, the lattice formed by carbon atoms in the graphene phase can be rolled up to form nanotubes of various dimensions. Graphene nanotubes have many important applications, some of which rely on their unusual electrical conductivity and related properties. Quantum walks on graphs provide an abstract setting in which to study such transport properties independent of the other chemical and physical properties of a physical substance. They can thus be used to further the understanding of mechanisms behind such properties. We find that nanotube structures are significantly more efficient in transporting a quantum walk than cycles of equivalent size, provided the symmetry of the structure is respected in how they are used. We find faster transport on zig-zag nanotubes compared to armchair nanotubes, which is unexpected given that for the actual materials the armchair nanotube is metallic, while the zig-zag is semiconducting.