Local Gating of an Ir(111) Surface Resonance by Graphene Islands

TL;DR

This study investigates how graphene islands locally modify the electronic surface resonance of Ir(111), revealing their role as nanoscale gates that influence surface electronic states through combined experimental and computational methods.

Contribution

It demonstrates that graphene islands can locally gate and confine surface resonances on Ir(111), combining scanning tunneling spectroscopy with density functional calculations.

Findings

Graphene islands shift and confine Ir(111) surface resonances.

Surface resonance has a binding energy of -160meV and an effective mass of -0.18m_e.

Nanometer-sized graphene acts as a local electronic gate.

Abstract

The influence of graphene islands on the electronic structure of the Ir(111) surface is investigated. Scanning tunneling spectroscopy (STS) indicates the presence of a two-dimensional electron gas with a binding energy of -160meV and an effective mass of -0.18m_e underneath single-layer graphene on the Ir(111) surface. Density functional calculations reveal that the STS features are predominantly due to a holelike surface resonance of the Ir(111) substrate. Nanometer-sized graphene islands act as local gates, which shift and confine the surface resonance.