# Resonance Absorption of Terahertz Radiation in Nanoperforated Graphene

## TL;DR

This paper investigates how nanoperforated graphene absorbs terahertz radiation, revealing valley-dependent resonance effects that can be tuned by gate voltage, based on edge state quantization near nanoholes.

## Contribution

It introduces a model linking edge state quantization in nanoholes to valley-specific terahertz absorption resonance in graphene.

## Key findings

- Resonance absorption occurs in one valley under circularly polarized terahertz radiation.
- Absorption magnitude at resonance can be tuned via gate voltage.
- Edge state quantization leads to a ladder of quasistationary energy levels.

## Abstract

Recent measurements of the conductivity of nanoperforated graphene are interpreted in terms of edges states existing near the edge of each nanohole. The perimetric quantization of edge states should result in the formation of a quasi-equidistant ladder of quasistationary energy levels. Dirac fermions filling this ladder rotate about each nanohole in the direction determined by the valley index. It is shown that the irradiation of this system by circularly polarized terahertz radiation leads to a resonance in absorption in one of the valleys. The magnitude of absorption at the resonance frequency can be controlled by means of gate voltage.