Metasurface electron optics in graphene

TL;DR

This paper introduces Dirac fermion metasurfaces in graphene, enabling precise electron wavefront shaping at room temperature with high efficiency, which could revolutionize quantum device performance.

Contribution

The paper presents the concept of electronic metasurfaces in graphene, allowing sub-wavelength control of electron waves at ambient conditions, surpassing previous size and temperature limitations.

Findings

Wavefront shaping within a single quantum dot diameter

Operation at room temperature with high efficiency

Fast tunability among multiple functionalities

Abstract

For electron optics in graphene, the propagation effect has so far been the only physical mechanism available. The resulting electron-optics-based components are large in size and operate at low temperatures to avoid violating the ballistic transport limits. In this paper, Dirac fermion metasurfaces, electronic counterparts of optical metasurfaces, are introduced for graphene electronics. By a metasurface, formally a linear array of gate-bias-controlled circular quantum dots, the wavefront of electron beams can be shaped within a one-quantum-dot-diameter distance, far below the ballistic limits at room temperature. This provides opportunities to create electron-optics-based devices that operate under ambient conditions. Moreover, unlike optical metasurfaces, Dirac fermion metasurfaces have near-perfect operating efficiencies and their high tunability allows for free and fast switching among functionalities. The concept of metasurface electron optics might open up a promising avenue for improving the performance of quantum devices in Dirac fermion materials.