Coexistence of Ballistic and Fourier Regimes in the β Fermi-Pasta-Ulam-Tsingou Lattice.,Physical Review Letters

当前位置： X-MOL 学术 › Phys. Rev. Lett. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Coexistence of Ballistic and Fourier Regimes in the β Fermi-Pasta-Ulam-Tsingou Lattice.
Physical Review Letters ( IF 8.1 ) Pub Date : 2020-07-07 , DOI: 10.1103/physrevlett.125.024101
Giovanni Dematteis ₁ , Lamberto Rondoni ₂ , Davide Proment ₃ , Francesco De Vita ₁ , Miguel Onorato _{1,

4}

Affiliation

Commonly, thermal transport properties of one-dimensional systems are found to be anomalous. Here, we perform a numerical and theoretical study of the

β

-Fermi-Pasta-Ulam-Tsingou chain, considered a prototypical model for one-dimensional anharmonic crystals, in contact with thermostats at different temperatures. We give evidence that, in steady state conditions, the local wave energy spectrum can be naturally split into modes that are essentially ballistic (noninteracting or scarcely interacting) and kinetic modes (interacting enough to relax to local thermodynamic equilibrium). We show numerically that the well-known divergence of the energy conductivity is related to how the transition region between these two sets of modes shifts in

k

space with the system size

L

, due to properties of the collision integral of the system. Moreover, we show that the kinetic modes are responsible for a macroscopic behavior compatible with Fourier’s law. Our work sheds light on the long-standing problem of the applicability of standard thermodynamics in one-dimensional nonlinear chains, testbed for understanding the thermal properties of nanotubes and nanowires.

中文翻译：

βFermi-Pasta-Ulam-Tssingou格中弹道和傅里叶体制的共存。

通常，发现一维系统的热传递特性是异常的。在这里，我们对

β

-Fermi-Pasta-Ulam-Tsingou链，被认为是一维非谐晶体的原型模型，在不同温度下与恒温器接触。我们提供的证据表明，在稳态条件下，本地波能谱可以自然地分为本质上是弹道（不相互作用或几乎不相互作用）和动力学模式（相互作用以放松到局部热力学平衡）的模式。我们用数字显示，众所周知，能量传导率的发散与这两组模式之间的过渡区域如何在