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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Mobile electrons in the semiconductor monolayer-MoS$_2$ form a ferromagneticstate at low temperature. The Fermi sea consists of two circles, one at the$K$-point, the other at the $\tilde{K}$-point, both with the same spin. Here,we present an optical experiment on gated MoS$_2$ at low electron-density inwhich excitons are injected with known spin and valley quantum numbers. Theresulting trions are identified using a model which accounts for the injectionprocess, the formation of antisymmetrized trion states, electron-holescattering from one valley to the other, and recombination. The results areconsistent with a complete spin polarization. From the splittings betweendifferent trion states, we measure the exchange energy, $\Sigma$, the energyrequired to flip a single spin within the ferromagnetic state, as well as theintervalley Coulomb exchange energy, $J$. We determine $\Sigma=11.2\,$meV and$J=5\,$meV at $n=1.5 \times 10^{12}\,$cm$^{-2}$, and find that $J$ dependsstrongly on the electron density, $n$.

Exchange energy of the ferromagnetic electronic ground-state in a monolayer semiconductor