Two-dimensional Weyl points and nodal lines in pentagonal materials and their optical response

Abstract

A symmetry analysis combined with first-principles calculations of two-dimensional pentagonal materials (PdSeTe, PdSeS, InP5 and GeBi2) based on the Cairo tiling reveal nontrivial spin textures, nodal lines and Weyl points.

Topological bands in the PdSe2 pentagonal monolayer

“…[5][6][7][8] Furthermore, the possibility of presenting topologically nontrivial phases has driven the interest towards other pentagonal layers with different compositions. [9][10][11][12] However, some theoretical proposals have been shown to be structurally unstable, especially those with dominant p-orbital bonds. 13,14 Notwithstanding, there are several instances of experimentally found 2D pentamaterials, such as PdSe 2 , PdS 2 and NiN 2 .…”

Layer-dependent ultrafast carrier dynamics of PdSe2 investigated by photoemission electron microscopy

“…Pentagonal two-dimensional (2D) materials, such as unitary compounds ( penta-graphene), 1 binary compounds(PdS 2 , PdSe 2 , TaB, TaC, NiN 2 ), [2][3][4][5][6][7] and trinary compounds (PdSeTe, PdPSe), [8][9][10] have attracted great attention in recent years, owing to their unique crystal structure and extraordinary properties in optics, electronics, optoelectronics and magnetism. [11][12][13] PdSe 2 with a wrinkled pentagonal structure exhibits exotic physicochemical properties, excellent anisotropy and stability, promising great prospective applications in optoelectronics, energy storage, catalysis, etc.…”

Recent advances in 2D TMD circular photo-galvanic effects

“…It is also an interesting and possibly valuable phenomenon. 5,39,40 Topological effects are becoming more popular, because they have important and unique uses in the physics of condensed matter. [41][42][43][44] The quantum Hall system is the only way to show the topological effect in the insulating phase in addition to being important at a fundamental level, and it has been used as a resistance metrological standard.…”