English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Two-dimensional Dirac semimetals have attracted much attention because oftheir linear energy dispersion and non-trivial Berry phase. Graphene-like 2DDirac materials are gapless only within certain approximations, e.g., ifspin-orbit coupling (SOC) is neglected. It has recently been reported thatmaterials with nonsymmorphic crystal lattice possess symmetry-enforcedDirac-like band dispersion around certain high-symmetry momenta even in thepresence of SOC. Here we calculate the optical absorption coefficient ofnonsymmorphic semimetals, such as $\alpha$-bismuthene, which hosts twoanisotropic Dirac cones with different Fermi velocities along $x$ and $y$directions.We find that the optical absorption coefficient depends strongly onthe anisotropy factor and the photon polarization. When a magnetic field isapplied perpendicular to the plane of the material, the absorption coefficientalso depends on an internal parameter we termed the mixing angle of the bandstructure. We further find that an in-plane magnetic field, while leaving thesystem gapless, can induce a Van-Hove singularity in the joint density ofstates: this causes a significant enhancement of the optical absorption at thefrequency of the singularity for one direction of polarization but not for theorthogonal one, making the optical properties even more strongly dependent onpolarization. Due to the anisotropy present in our model, the Dirac cones attwo high-symmetry momenta in the Brillouin zone contribute very differently tothe optical absorbance. Consequently, it might be possible to preferentiallypopulate one valley or the other by varying photon polarization and frequency.These results suggest that nonsymmorphic 2D Dirac semimetals are excellentcandidate materials for tunable magneto-optic devices.

Photon Absorption of Two-dimensional Nonsymmorphic Dirac Semimetals