Journal article

A Single Chiral Nanoparticle Induced Valley Polarization Enhancement

Sejeong Kim, Yae-Chan Lim, Ryeong Myeong Kim, Johannes E Froech, N Tran Thinh, Ki Tae Nam, Igor Aharonovich

SMALL | WILEY-V C H VERLAG GMBH | Published : 2020

Abstract

Valley polarization is among the most critical attributes of atomically thin materials. However, increasing contrast from monolayer transition metal dichalcogenides (TMDs) has so far been challenging. In this work, a large degree of circular polarization up to 45% from a monolayer WS2 is achieved at room temperature by using a single chiral plasmonic nanoparticle. The increased contrast is attributed to the selective enhancement of both the excitation and the emission rate having one particular handedness of the circular polarization, together with accelerated radiative recombination of valley excitons due to the Purcell effect. The experimental results are corroborated by the optical simula..

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Grants

Awarded by Australian Research Council


Awarded by Creative Materials Discovery Program through the National Research Foundation of Korea (NRF) - Ministry of Science and ICT


Funding Acknowledgements

The authors are grateful for fruitful discussions with Dr. Su-Hyung Gong and acknowledge the support by Australian Research Council (DP180100077) and Creative Materials Discovery Program through the National Research Foundation of Korea (NRF) funded by Ministry of Science and ICT (NRF-2017M3D1A1039377). K.T.N. appreciates the support from the Institute of Engineering Research, Research Institute of Advanced Materials (RIAM), and Soft Foundry at Seoul National University.