Valley filters, accumulators, and switches induced in graphene quantum dots by lines of adsorbed hydrogen atoms

TL;DR

This paper predicts that lines of adsorbed hydrogen atoms on graphene quantum dots can create highly efficient valley filters, accumulators, and switches by exploiting a novel Dirac point resonance property that allows valley-specific electron conduction.

Contribution

The study introduces a new physical mechanism in graphene quantum dots where hydrogen lines induce valley-specific conduction channels via Dirac point resonances.

Findings

Hydrogen lines induce valley-specific conducting channels.

These channels can function as filters, accumulators, and switches.

Predictions apply to free-standing and supported graphene quantum dots.

Abstract

We present electronic structure and quantum transport calculations that predict conducting channels induced in graphene quantum dots by lines of adsorbed hydrogen atoms to function as highly efficient, experimentally realizable valley filters, accumulators and switches. The underlying physics is a novel property of graphene Dirac point resonances (DPRs) that is revealed here, namely, that an electric current passing through a DPR-mediated conducting channel in a given direction is carried by electrons of em only one of the two graphene valleys. Our predictions apply to lines of hydrogen atoms adsorbed on graphene quantum dots that are either free standing or supported on a hexagonal boron nitride substrate.