Discrete breathers: possible effects on heat transport
Discrete breathers: possible effects on heat transport
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离散通气装置：对热传输可能产生的影响
DOI：
10.22226/2410-3535-2016-1-27-30
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发表时间：
2016-03
影响因子：
0.7
通讯作者：
Jun Zhang
中科院分区：
文献类型：
--
作者：
Daxing Xiong;Jun Zhang
离散呼吸模（DBs），也称为本征局域模，是无缺陷非调和晶格中的空间局域非线性振动模，预计会影响能量传递过程。然而，db是否能在有限温度下参与热输运尚不清楚。在目前的工作中，我们简要地描述了我们最近关于db对热传递可能影响的研究结果。利用两个具有不同声子色散的一维非调和晶格模型，我们提供了一些数值证据，证明在给定特殊的声子色散和非线性的情况下，带内和带外两种波波导可以在有限温度下存在于一维晶格中，从而以不同的方式促进热输运，即带内波波导可以被声子散射；而带外db主要将系统能量局域化，因此两者都倾向于将热输运限制在热力学极限。我们的研究结果表明，不同的特殊声子色散以及非线性可以使我们激发不同类型的db，从而以不同的方式影响热传递过程。这些结果可以为建立具有不同声子色散的一维非线性系统的宏观热输运过程与底层db动力学之间的联系提供有用的信息。
Discrete breathers (DBs), also known as intrinsic localized modes, are spatially localized nonlinear vibrational modes in defected-free anharmonic lattices and expected to affect energy transfer process. However, whether DBs can contribute to thermal transport at finite temperature is still not very clear. In the present work, we briefly describe our recent results on the possible effects of DBs on heat transport. By employing two one-dimensional (1D) anharmonic lattice models with different phonon dispersions, we provide some numerical evidences to demonstrate that given the peculiar phonon dispersions along with nonlinearity, two kinds of DBs, i.e., the intra-band and extra-band ones, can exist in 1D lattices at finite temperature and thus contribute to thermal transport in different ways, i.e., the intra-band DBs can be scattering with phonons; while the extra-band DBs mainly localize the system energies, thus both tend to limit the heat transport in the thermodynamic limit. Our results here suggest that different peculiar phonon dispersions along with nonlinearity can enable us to excite different types of DBs, which then affect the heat transport process in different ways. These results may provide useful information for establishing the connection between the macroscopic heat transport process and the underlying DBs dynamics in general 1D nonlinear systems with various phonon dispersions.