**Nonequilibrium generalised Langevin equation for the calculation of heat
transport properties in model 1D atomic chains coupled to two 3D thermal
baths**

H Ness and L Stella and CD Lorenz and L Kantorovich, JOURNAL OF CHEMICAL PHYSICS, 146, 164103 (2017).

DOI: 10.1063/1.4981816

We use a generalised Langevin equation scheme to study the thermal
transport of low dimensional systems. In this approach, the central
classical region is connected to two realistic thermal baths kept at two
different temperatures **H. Ness et al., Phys. Rev. B 93, 174303 (2016)**.
We consider model Al systems, i.e., one-dimensional atomic chains
connected to three-dimensional baths. The thermal transport properties
are studied as a function of the chain length N and the temperature
difference Delta T between the baths. We calculate the transport
properties both in the linear response regime and in the non-linear
regime. Two different laws are obtained for the linear conductance
versus the length of the chains. For large temperatures (T greater than
or similar to 500 K) and temperature differences (Delta T greater than
or similar to 500 K), the chains, with N > 18 atoms, present a diffusive
transport regime with the presence of a temperature gradient across the
system. For lower temperatures (T less than or similar to 500 K) and
temperature differences (Delta T less than or similar to 400 K), a
regime similar to the ballistic regime is observed. Such a ballistic-
like regime is also obtained for shorter chains (N <= 15). Our detailed
analysis suggests that the behaviour at higher temperatures and
temperature differences is mainly due to anharmonic effects within the
long chains. Published by AIP Publishing.

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