Large positive magnetoconductance in carbon nanoscrolls

TL;DR

This paper theoretically shows that carbon nanoscrolls exhibit a large positive magnetoconductance due to magnetic field-induced zero energy modes, which is robust even with disorder, highlighting their potential for magnetoresistive applications.

Contribution

The study reveals that carbon nanoscrolls have a significant positive magnetoconductance driven by magnetic field-induced zero energy modes, even in the presence of disorder.

Findings

Ballistic conductance increases by about 200% under a few Tesla magnetic field.

Positive magnetoconductance persists and can be enhanced with disorder.

Magnetoconductance is linked to magnetic field-induced zero energy modes.

Abstract

We theoretically demonstrate that carbon nanoscrolls -- spirally wrapped graphene layers with open endpoints -- can be characterized by a large positive magnetoconductance. We show that when a carbon nanoscroll is subject to an axial magnetic field of several Tesla, the ballistic conductance at low carrier densities of the nanoscroll has an increase of about 200%. Importantly, we find that this positive magnetoconductance is not only preserved in an imperfect nanoscroll (with disorder or mild inter-turn misalignment) but can even be enhanced in the presence of on-site disorder. We prove that the positive magnetoconductance comes about the emergence of magnetic field-induced zero energy modes, specific of rolled-up geometries. Our results establish curved graphene systems as a new material platform displaying sizable magnetoresistive phenomena.