Seminário de grupo da próxima terça-feira, 25 de setembro

O Seminário de Óptica da próxima terça-feira, 25 de setembro será apresentado pelo Prof. Fabrice Vallee.

O Seminário de Óptica da próxima terça-feira, 25 de setembro (14 horas, no auditório do Departamento de Física/UFPE) será apresentado pelo Prof. Fabrice Vallee (ILM - CNRS, Universite Lyon 1, France).
Título: Time-resolved optical investigation of the acoustic response of metal nanoparticles: from macro- to nano-size mechanical resonators
Resumo: Controlling and modeling the mechanical response of nanoscale systems is of central interest for many technological applications. In this size range, breaking of translational invariance leads to appearance of discrete acoustic modes that find application in different domains and also rule many fundamental properties of nano-materials. The acoustic mode frequencies of nano-objects down to the one nanometer size are well described in the framework of the elasticity model [1,2]. For smaller sizes, deviations are experimentally observed suggesting description of the vibrational modes should rather be performed with an atomistic approach rather than with a “macroscopic” elastic body one. Using optical time-resolved spectroscopy, we show that this two approaches yield similar results down to the one nanometer scale, provided the environment of the nano-objects is properly taken into account. Acoustic vibration damping and its control will also be discussed, on the basis of time-resolved investigations of the acoustic vibration of single supported metal nano-objects. 


[1] A. Crut et al., Physics Report 549, 1 (2015)

[2] H. E. Sauced-Félix et al., J. Phys. Chem C 116, 25147 (2012).

Data da última modificação: 21/09/2018, 10:28