4 research outputs found
Valley-addressable polaritons in atomically thin semiconductors
The locking of the electron spin to the valley degree of freedom
in transition metal dichalcogenide (TMD) monolayers has seen
these materials emerge as a promising platform in valleytronics.
When embedded in optical microcavities, the large oscillator
strengths of excitonic transitions in TMDs allow the
formation of polaritons that are part-light part-matter quasiparticles.
Here, we report that polaritons in MoSe2 show an
efficient retention of the valley pseudospin contrasting them
with excitons and trions in this material. We find that the
degree of the valley pseudospin retention is dependent on
the photon, exciton and trion fractions in the polariton states.
This allows us to conclude that in the polaritonic regime,
cavity-modified exciton relaxation inhibits loss of the valley
pseudospin. The valley-addressable exciton-polaritons and
trion-polaritons presented here offer robust valley-polarized
states with the potential for valleytronic devices based on
TMDs embedded in photonic structures and valley-dependent
nonlinear polaritonâpolariton interactions