Physics – Condensed Matter – Statistical Mechanics
Scientific paper
2011-05-11
Physics
Condensed Matter
Statistical Mechanics
7 pages, 9 figures
Scientific paper
We study the flow of heat in a finite linear chain by solving the Heisenberg equation of motion of lattice vibrations and using nonequilibrium Green's functions to calculate the heat current. The initial state of the system consists of two separate and finite linear chains in respective equilibrium at different temperatures. The left and right edges of each of the chains are attached to fixed walls. At time zero, the chains are abruptly connected, through the application of an external energy, to form a composite linear chain. Since the chains initially have different temperatures, heat would begin to flow from the hotter to the cooler chain. However, since the chains are finite and are attached non-adiabatically, steady-state heat flow is not immediately established. The transient current just after connection, in particular, reflects the in-flow of the extra energy added to fuse the two chains together. Furthermore, our results suggest that a quasi-steady-state current can not be established without the presence of an on-site potential acting at each particle in the chain. Without an on-site potential, the phonons simply bounce back and forth between the two fixed walls at the edges of the composite chain. In the presence of an on-site potential, the speed at which a quasi-steady state is approached depends on the interplay between the strength of the on-site potential, the chain length, and the initial temperature of the chains. For a given chain length and temperature, the quasi-steady state is approached faster when the on-site potential is stronger. In addition, the quasi-steady-state value of the heat current coincides with the steady-state value predicted by the Landauer formula and the long-time value of the current in infinitely-long chains.
Cuansing Eduardo C.
Li Huanan
Wang Jian-Sheng
No associations
LandOfFree
Surprising role of the on-site potential in establishing quasi-steady-state conditions in heat transport in finite quantum systems does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Surprising role of the on-site potential in establishing quasi-steady-state conditions in heat transport in finite quantum systems, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Surprising role of the on-site potential in establishing quasi-steady-state conditions in heat transport in finite quantum systems will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-611876