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

In monolayers of the semiconducting transition metal dichalcogenides, theelectron-hole exchange interaction splits the exciton dispersion into a massivetransverse branch, and a longitudinal branch that has very light or even zeromass depending on the form of screened Coulomb interaction. The group velocityof the longitudinal branch is sensitive to the strength of electron-holeexchange, which can be engineered through the dielectric environment. Here weshow that dielectric patterning of the substrate can be exploited to realizewaveguide of the exciton in the longitudinal branch in a homogeneous monolayer,leaving the massive transverse branch unaffected. At a lateral interface ofdifferent dielectric constant in the substrate, the transmission and reflectionof exciton in the longitudinal branch obey the Snell-Descartes law of opticalsystem, and total reflection can be exploited to realize excitonic waveguideusing two parallel interfaces. The same dielectric pattern of the substrateappears to be completely transparent for the massive transverse branch exciton,which has no interface scattering. When the monolayer is placed on aone-dimensional dielectric superlattice, the dispersion of the longitudinalbranch is strongly renormalized, and the wavefunctions exhibit one-dimensionalfeatures, confined to either the low-dielectric or high-dielectric regions. Incontrast, the massive transverse branch excitons are not affected by thesubstrate dielectric pattern, exhibiting pristine properties as in afreestanding monolayer.

Waveguiding valley excitons in monolayer transition metal dicalcogenides by dielectric interfaces in the substrate