A chain, a bath, a sink and a wall

Stefano Iubini, Stefano Lepri, Roberto Livi, Gian-Luca Oppo, Antonio Politi

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

We numerically investigate out-of-equilibrium stationary processes emerging in a Discrete Nonlinear Schrödinger chain in contact with a heat reservoir (a bath) at temperature TL and a pure dissipator (a sink) acting on opposite edges. Long-time molecular-dynamics simulations are performed by evolving the equations of motion within a symplectic integration scheme. Mass and energy are steadily transported through the chain from the heat bath to the sink. We observe two different regimes. For small heat-bath temperatures TL and chemical-potentials, temperature profiles across the chain display a non-monotonous shape, remain remarkably smooth and even enter the region of negative absolute temperatures. For larger temperatures TL, the transport of energy is strongly inhibited by the spontaneous emergence of discrete breathers, which act as a thermal wall. A strongly intermittent energy flux is also observed, due to the irregular birth and death of breathers. The corresponding statistics exhibit the typical signature of rare events of processes with large deviations. In particular, the breather lifetime is found to be ruled by a stretched-exponential law.
LanguageEnglish
Article number445
Number of pages15
JournalEntropy
Volume19
Issue number9
DOIs
Publication statusPublished - 25 Aug 2017

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sinks
baths
heat
temperature
death
temperature profiles
energy
emerging
equations of motion
dissipation
signatures
statistics
molecular dynamics
deviation
life (durability)
simulation

Keywords

  • discrete nonlinear schrödinger
  • discrete breathers
  • negative temperatures
  • open systems

Cite this

Iubini, Stefano ; Lepri, Stefano ; Livi, Roberto ; Oppo, Gian-Luca ; Politi, Antonio. / A chain, a bath, a sink and a wall. In: Entropy. 2017 ; Vol. 19, No. 9.
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A chain, a bath, a sink and a wall. / Iubini, Stefano; Lepri, Stefano; Livi, Roberto; Oppo, Gian-Luca; Politi, Antonio.

In: Entropy, Vol. 19, No. 9, 445, 25.08.2017.

Research output: Contribution to journalArticle

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AU - Iubini, Stefano

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