Complex Structure of Triangular Graphene: Electronic, Magnetic and Electromechanical Properties

TL;DR

This paper explores the electronic, magnetic, and electromechanical properties of triangular graphene nanodisks and junctions, proposing novel spintronic devices, nanomechanical switches, and sensors based on their unique characteristics.

Contribution

It introduces new insights into graphene nanodisk properties and proposes innovative device concepts like spin filters, nanomechanical switches, and stretch sensors utilizing these properties.

Findings

Graphene nanodisks exhibit robust ferromagnetism due to Lieb's theorem.

Proposed nanomechanical switch and rotator can detect tiny angle rotations via current measurements.

Strain-induced Peierls transition enables nanomechanical stretch sensors with conductance switching.

Abstract

We have investigated electronic and magnetic properties of graphene nanodisks (nanosize triangular graphene) as well as electromechanical properties of graphene nanojunctions. Nanodisks are nanomagnets made of graphene, which are robust against perturbation such as impurities and lattice defects, where the ferromagnetic order is assured by Lieb's theorem. We can generate a spin current by spin filter, and manipulate it by a spin valve, a spin switch and other spintronic devices made of graphene nanodisks. We have analyzed nanodisk arrays, which have multi-degenerate perfect flat bands and are ferromagnet. By connecting two triangular graphene corners, we propose a nanomechanical switch and a rotator, which can detect a tiny angle rotation by measuring currents between the two corners. By making use of the strain induced Peierls transition of zigzag nanoribbons, we also propose a nanomechanical stretch sensor, in which the conductance can be switch off by a nanometer scale stretching.