Tunable transmittance in anisotropic 2D materials

TL;DR

This paper investigates how uniaxial strain affects the optical properties of anisotropic 2D materials like black phosphorus, demonstrating tunable transmittance from nearly 0% to almost 100% in microwave and far-infrared regimes.

Contribution

It introduces a method to determine spectral and transport properties in strained black phosphorus and shows how optical transmittance can be actively tuned.

Findings

Transmittance varies from 0% to nearly 100% in specific regimes.

Uniaxial strain induces anisotropy affecting optical properties.

Proposed method aids in characterizing strained 2D materials.

Abstract

A uniaxial strain applied to graphene-like materials moves the Dirac nodes along the boundary of the Brillouin zone. An extreme case is the merging of the Dirac node positions to a single degenerate spectral node which gives rise to a new topological phase. Then isotropic Dirac nodes are replaced by a node with a linear behavior in one and a parabolic behavior in the other direction. This anisotropy influences substantially the optical properties. We propose a method to determine characteristic spectral and transport properties in black phosphorus layers which were recently studied by several groups with angle-resolved photoemission spectroscopy, and discuss how the transmittance, the reflectance and the optical absorption of this material can be tuned. In particular, we demonstrate that the transmittance of linearly polarized incident light varies from nearly 0\% to almost 100\% in the microwave and far-infrared regime.