Mechanical Anisotropy and Multiple Direction-Dependent Dirac States in the Synthesized Ag3C20 Monolayer

TL;DR

This study reveals that the synthesized Ag3C20 monolayer exhibits significant mechanical anisotropy and hosts various tunable, direction-dependent Dirac states, making it a promising material for advanced electronic applications.

Contribution

The paper demonstrates for the first time the presence of multiple tunable Dirac states and strong mechanical anisotropy in the Ag3C20 monolayer through first-principles calculations.

Findings

Ag3C20 monolayer exhibits strong mechanical anisotropy.

Presence of antiparallel quasi type-III nodal lines protected by mirror symmetry.

Emergence of semi-Dirac states under strain with unique electronic properties.

Abstract

Recently, a 2D orthorhombic silver-organic framework, Ag3C20 monolayer, was synthesized by assembling organic molecules linked with multiple aryl-metal bonds. Herein, via first-principles study, we demonstrate that owing to the unique bonding feature, Ag3C20 monolayer not only exhibits strong mechanical anisotropy, but also possesses various tunable direction-dependent Dirac states. Around the Fermi level blow, the intrinsic Dirac points form two antiparallel quasi type-III nodal lines protected by mirror symmetry, which can further evolve into hybrid nodal loops under tiny strains. Intriguingly, near the Fermi level above, a special semi-Dirac state can emerge under a critical strain by merging two type-I Dirac cone, which harbors direction-dependent strongly localized fermions, normal massive carries, and ultrafast Dirac fermions at the same time. These findings suggest that the mechanically sensitive Ag3C20 monolayer is a promising 2D material to realize the interesting Dirac physics and highly anisotropic multiple carries transport.