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arXiv · 1909.05290

Real-time observation of spin-resolved plexcitons between metal plasmons and excitons of WS$_2$

Rup Kumar Chowdhury·Prasanta Kumar Datta·Shivakiran Bhaktha BN·Samit Kumar Ray
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Abstract

Strong light-matter interactions between resonantly coupled metal plasmons and spin decoupled bright excitons from two dimensional (2D) transition metal dichalcogenides (TMDs) can produce discrete spin-resolved exciton-plasmon polariton (plexciton). A few efforts have been made to perceive the spin induced exciton-polaritons in nanocavities at cryogenic conditions, however, successful realization of spin-resolved plexciton in time-domain is still lacking. Here, we are able to identify both the spin-resolved plexcitons discretely at room temperature and investigate their ultrafast temporal dynamics in size-tunable $Au-WS_{2}$ hybrid nanostructures using femtosecond pump-probe spectroscopy technique. Furthermore, we attribute that zero detuning between the excitons and plasmons is achieved at $\sim$7.0 ps along with transient Rabi-splitting energy exceeding $\sim$250 meV for both the spin-plexcitons, validating the strong-coupling conditions of polariton formation. Realization of these novel spin-plexcitons in the metal-TMDs platform is, therefore, interesting for both fundamental understanding and their possible futuristic applications in quantum photonics operating at room temperature.

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Rup Kumar Chowdhury, Prasanta Kumar Datta, Shivakiran Bhaktha BN, Samit Kumar Ray. 2019-09-11. Real-time observation of spin-resolved plexcitons between metal plasmons and excitons of WS$_2$. https://arxiv.org/abs/1909.05290

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