Título: | NONLINEAR BROWNIAN MACHINES | ||||||||||||
Autor: |
LUCIANNO AUGUSTO CODDATO ANTUNES E DEFAVERI |
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Colaborador(es): |
WELLES ANTONIO MARTINEZ MORGADO - Orientador SILVIO MANUEL DUARTE QUEIROS - Coorientador |
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Catalogação: | 06/ABR/2021 | Língua(s): | ENGLISH - UNITED STATES |
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Tipo: | TEXT | Subtipo: | THESIS | ||||||||||
Notas: |
[pt] Todos os dados constantes dos documentos são de inteira responsabilidade de seus autores. Os dados utilizados nas descrições dos documentos estão em conformidade com os sistemas da administração da PUC-Rio. [en] All data contained in the documents are the sole responsibility of the authors. The data used in the descriptions of the documents are in conformity with the systems of the administration of PUC-Rio. |
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Referência(s): |
[pt] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=52053&idi=1 [en] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=52053&idi=2 |
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DOI: | https://doi.org/10.17771/PUCRio.acad.52053 | ||||||||||||
Resumo: | |||||||||||||
In the recent decade we have seen great interest in the physics of
single particle microscopic engines. Not only we have seen advances in the
theoretical understanding of how such systems behave but also, thanks
to the advanced level of microscopic manipulations, we are capable of
reproducing these systems in experimental situations. The literature is quite
large when considering machines where a single particle is subjected to a
harmonic potential where we can control the stiffness and in contact with
a heat bath of controllable temperature. Motivated by these outstanding
results, we have decided to investigate an alternative mechanism to studying
machines. We propose and investigate a setup where a single particle with
an internal nonlinear potential in contact with a heat bath of temperature
T that we can control, then we introduce an external quadratic potential
centered in a position L which will break the internal symmetry and create
a direction where the particle can fluctuate to with greater ease. We can
use this symmetry breaking to convert heat into work. Starting with a
nonlinear correction to a predominantly linear internal potential, we use
perturbation theory to solve the Langevin equation of the system up to the
first order o k4 and obtain the expected work and absorbed heat. We then
relax the restriction of a small nonlinear by imposing that the cycle periods
are so large that, at least to some extent, the system can be considered
in equilibrium with the heat bath. Using classical statistical mechanics we
obtain results for a wider range of nonlinearities. Since the key component of
our machines is the asymmetry, we extend the internal potential to the more
general but not always analytical form V(i)(x) proportional to (x) raised to alpha which we label alpha-typepotential. Using primarily numerical techniques investigate its properties
and outputs for different values of alpha. Lastly we study the Carnot cycle
by replacing the adiabatical branches with isentropic ones, investigating
the relationship between alpha and the isentropic trajectories. All results are
compared with numerical simulations.
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