Room-temperature ballistic transport in narrow graphene strips

TL;DR

This paper demonstrates that narrow graphene strips exhibit near-ballistic electron transport at room temperature due to suppressed electron-phonon scattering, with mean free paths reaching tens of micrometers.

Contribution

It reveals that boundary conditions in narrow graphene strips significantly reduce electron-phonon scattering, enabling ballistic transport at room temperature.

Findings

Electron-phonon mean free path is proportional to nanostrip width.

Mean free path can reach approximately 70 μm in 11-nm-wide strips.

Suppressed backscattering channels lead to high mobility.

Abstract

We investigate electron-phonon couplings, scattering rates, and mean free paths in zigzag-edge graphene strips with widths of the order of 10 nm. Our calculations for these graphene nanostrips show both the expected similarity with single-wall carbon nanotubes (SWNTs) and the suppression of the electron-phonon scattering due to a Dirichlet boundary condition that prohibits one major backscattering channel present in SWNTs. Low-energy acoustic phonon scattering is exponentially small at room temperature due to the large phonon wave vector required for backscattering. We find within our model that the electron-phonon mean free path is proportional to the width of the nanostrip and is approximately 70 $\mu$m for an 11-nm-wide nanostrip.