Visualizing Nonlinear Phononics in Layered ReSe2.
J Phys Chem Lett
; 12(21): 5178-5184, 2021 Jun 03.
Article
em En
| MEDLINE
| ID: mdl-34037407
ABSTRACT
Nonlinear phononics has recently been demonstrated as a viable approach for dynamically modifying materials' properties. Conventionally, nonlinearity in the lattice dynamics is introduced via the "ionic" Raman scattering, in which infrared-active phonons (i.e., coherent ionic vibrations) serve as the intermediate state for transferring energy to Raman-active phonons. Here we report that it is also possible to achieve phononic nonlinearity through the "electronic" route, a process that relies on excited electronic states to initiate energy exchange among Raman-active phonons. Taking layered ReSe2 as a model system, we use coherent phonon spectroscopy with a pump energy larger than the band gap to follow lattice dynamics and observe the nonlinear coupling between both Raman-active intralayer atomic oscillations and interlayer breathing modes. In addition, we show that such nonlinear phononic coupling is highly dependent on the environment temperature. This work, which demonstrates a different and novel mechanism, may enrich the toolkit for controlling material properties by means of nonlinear phononics.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
J Phys Chem Lett
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
China