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 Tools annual

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 monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

A monolayer of a transition metal dichalcogenide (TMD) such as WSe$_2$ is atwo-dimensional (2D) direct band-gap valley-semiconductor having an effectiveHoneycomb lattice structure with broken inversion symmetry. The inequivalentvalleys in the Brillouin zone could be selectively addressed usingcircularly-polarized light fields, suggesting the possibility formagneto-optical measurement and manipulation of the valley pseudospin degree offreedom. Here we report such experiments that demonstrate the valley Zeemaneffect -- strongly anisotropic lifting of the degeneracy of the valleypseudospin degree of freedom using an external magnetic field. While thevalley-splitting measured using the exciton transition is consistent with thedifference of the conduction and valence band orbital magnetic moments, thetrion transition exhibits an unexpectedly large valley Zeeman effect whichcannot be understood using an independent electron-hole picture. Instead, wefind an explanation using the recently predicted large Berry curvature and theassociated magnetic moment for the electron-hole exchange interaction modifiedtrion dispersion. Our results raise the possibility of observing opticalexcitation induced valley Hall effect in monolayer TMDs or topological statesof photons strongly coupled to trion excitations in a microcavity.

Valley Zeeman Effect in Elementary Optical Excitations of a Monolayer WSe2