Seminar - Strong plasmon-exciton interactions at a single nanoantenna level

June 28, 14:00, CEITEC, S building, large meeting room   

Timur Shegai  

Chalmers University of Technology  

Monolayer transition metal dichalcogenides (TMDC) exhibit interesting optical properties, including sharp and intense (up to 20%) absorption features even at room temperature, valley degree of freedom and existence of trions. These materials are fairly stable and easy to exfoliate thanks to their van der Waals nature. The length scale of exciton physics in these materials match that of collective surface plasma oscillations – surface plasmons – in nanostructured gold and silver particles, which in turn open possibilities for studying strong light-matter interactions in these nanoscopic systems. In this talk I will show that exciton-plasmon interactions between mono- and multilayer TMDCs and individual plasmonic nanoantennas can reach the level of strong coupling, also known as vacuum Rabi splitting [1]. Specifically, I will discuss formation of hybrid exciton-trion-plasmon polaritons in monolayer WS2 – silver nanoprism system [2], spatially confined strong exciton-plasmon interaction between mono- and multilayer WSe2 and gold bipyramids [3], as well as hierarchical microcavity-plasmon-exciton polaritons encompassing monolayer WS2, arrays of gold nanodisks and Fabry-Pérot microcavity [4].


References:

1.         Baranov, D.G., et al. ACS Photonics, 2017. 5: p. 24.

2.         Cuadra, J., et al. Nano Lett., 2018. 18: p. 1777.

3.         Stührenberg, M., et al. Nano Letters, 2018. 18(9): p. 5938-5945.

4.         Bisht, A., et al. Nano Letters, 2018.


The Scientific Center for Optical and Electron Microscopy (ScopeM) is a facility created through a concerted effort of the Professors and Executive Board of the ETH Zurich in order to offer access to a collection of state-of-the-art light microscopy (LM), electron microscopy (EM) and related sample preparation equipment. In addition, the staff of ScopeM offers consultation, training and microscopy services. The role of ScopeM is to support vital research efforts and services primarily for ETH employees and visiting scientists; it is also open to external academic and industrial users. 

ScopeM has two main technological branches. The LM branch operates a wide variety of light microscopy systems ranging from the routine wide-field systems to the high-end super-resolution ones. The portfolio includes also histology and lab-automation  equipment (high-throughput screening) and dedicated correlative systems (e.g. CLEM). The EM branch runs a number of (cryo) analytical S/TEMs, (cryo) FIB/SEMs, serial sectioning in-situ SEM and high resolution analytical SEMs. The acquisition and processing of images/data are also supported by ScopeM experts in image and data processing.