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Volume 4, Issue 2 (Suppl) J Laser Opt Photonics, an open access journal
ISSN: 2469-410X
Page 28
conferenceseries.com JOINT EVENT
July 31- August 02, 2017 Milan, Italy
&
6th International Conference on Photonics
7th International Conference on Laser Optics
Fabienne Michelini
Aix Marseille University, France
Fabienne Michelini, J Laser Opt Photonics 2017, 4:2(Suppl)
DOI: 10.4172/2469-410X-C1-010
Energy transfer dynamics in molecular junctions under ultra-short excitation pulses from non-
equilibrium Green’s function formalism
The problem of energy transfer is emerging as one of the most crucial issues of our occidental societies. At a fundamental
level, how energy flows at the nanometre scale is gaining specific interests due to its implications in both alternative
energy production and basics of quantum thermodynamics. The nature of our work is hence two-fold. In the first part, we
provide a definition of energy current operator in the Heisenberg representation, while discussing certain conditions which
an operator shall fulfill. The obtained expression is applicable to non-stationary as steady-state situations. We implement this
definition to derive time-dependent energy current using non-equilibrium Green’s function formalism, which represents a
suitable approach for calculating measurable quantities in opened nanosystems. The second part applies these developments
to molecular junctions sandwiched in between two thermal reservoirs. Molecular electronic devices are indeed a promising
alternative to standard electronic switches due to their fast response on the picosecond time scale. Here, the approach is used
for the study of molecular junctions subjected to ultra-short excitation pulses. We thus analyze the electronic energy fluxes
across the molecular junction engendered by femtosecond laser pulses. Our numerical implementation enables us to correlate
the time-dependent energy current to the underlying intra-molecular dynamics, with special attention paid to the impacts of
intra-molecular coupling and incoherence on the energy transfer time-resolved measurables.
Figure1: We consider a junction made of two donors (D) that interact with light and an acceptor (A), the whole
is in contact with tow thermal reservoirs. Effects of the intra-molecular D-D coupling on the time-resolved energy
current flowing from D to A during a 30 fs laser pulse
Biography
Fabienne Michelini has worked on the theoretical/numerical building of empirical models within the k•p method to understand the electronic properties of realistic con-
densed-matter systems. In parallel, she has gained a great expertise in high performance computing for large-scale numerical problems. For the last years, she has inves-
tigated the transport properties of opened quantum structures for novel nanodevices using effective methods within the Green function formalism. She is now focusing on
time-dependent and non-linear regimes of nanosystems interacting with light for optoelectronic and thermoelectric applications at the nanoscale.