2,605 research outputs found
Double negative differential thermal resistance induced by the nonlinear on-site potentials
We study heat conduction through one-dimensional homogeneous lattices in the
presence of the nonlinear on-site potentials containing the bounded and
unbounded parts, and the harmonic interaction potential. We observe the
occurrence of double negative differential thermal resistance (NDTR), namely,
there exist two regions of temperature difference, where the heat flux
decreases as the applied temperature difference increases. The nonlinearity of
the bounded part contributes to NDTR at low temperatures and NDTR at high
temperatures is induced by the nonlinearity of the unbounded part. The
nonlinearity of the on-site potentials is necessary to obtain NDTR for the
harmonic interaction homogeneous lattices. However, for the anharmonic
homogeneous lattices, NDTR even occurs in the absence of the on-site
potentials, for example the rotator model.Comment: 5 pages, 4 figure
Particle diode: Rectification of interacting Brownian ratchets
Transport of Brownian particles interacting with each other via the Morse
potential is investigated in the presence of an ac driving force applied
locally at one end of the chain. By using numerical simulations, we find that
the system can behave as a particle diode for both overdamped and underdamped
cases. For low frequencies, the transport from the free end to the ac acting
end is prohibited, while the transport from the ac acting end to the free end
is permitted. However, the polarity of the particle diode will reverse for
medium frequencies. There exists an optimal value of the well depth of the
interaction potential at which the average velocity takes its maximum. The
average velocity decreases monotonically with the system size by
a power law .Comment: 7 pages, 9 figure
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