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Convidamos toda a comunidade para participar do Ciclo de Colóquios Online do IF-UFF 2020, dia 23 de Junho, às 11h

Palestrante: Leandro M Malard (Depto de Física - UFMG)

Título: Nonlinear optical spectroscopy and imaging in 2D materials

Sala de Videoconferência (Google Meet): https://meet.google.com/nrg-rjvq-nfa
o se esqueça de desabilitar o acesso à câmera e ao microfone do seu dispositivo ao entrar na sala. 
A exibição da sala de conferência será gravada e divulgada no Canal Youtube do Instituto de Física da UFF.

Link de Transmissão ao vivo : https://stream.meet.google.com/stream/37336e03-a072-4baa-b044-7a51da9559c4 (Acesso somente via iduff)

Veja a continuação desta notícia para um resumo.

 

Resumo: In this talk I will show our recent developments on the non-linear optical properties of novel 2D materials. We will give a brief introduction on non-linear optics, new developments in 2D materials and how to use non-linear optical techniques to study 2D materials. We have used both Second Harmonic Generation (SHG) and Coherent Anti Stokes Raman Scattering (CARS) to study mono- and few-layers of semiconducting dichalcogenides and graphene respectively. In the case of the MoS2 we have observed efficient SHG from odd number of layers due to the absence of inversion symmetry [1]. By using different laser excitation energies, we could probe the resonant effect in the SHG in MoS2, MoSe2 and WS2. By analyzing the resonant profile of SHG we can observe the different types of excitons in this material, which are compared with recent theoretical results in the literature [2]. Because graphene have inversion symmetry, the SHG is almost absent, however third order nonlinearities are greatly enhanced in this material due its peculiar band structure. We will discuss the CARS process in graphene and h- BN [3]. More recently we have also shown that SHG can be a useful tool to identify and characterize grain boundaries and edges in different 2D materials [4].

[1] L. M. Malard et al., Phys. Rev. B 87, 201401 (2013).

[2] L. Lafetá et al., in preparation.

[3] L. Lafetá et al., Nano Lett. 17, 3447 (2017).

[4] B. R. Carvalho et al., Nano Lett. 20, 284 (2020).

Última actualización el Martes 30 de Junio de 2020 01:30