Nonequilibrium distribution of the microscopic thermal current is investigated by direct molecular dynamics simulations. The microscopic thermal current in this study is defined by a flow of kinetic energy carried by a single particle. Asymptotic parallel and antiparallel tails of the nonequilibrium distribution to an average thermal current are identical to ones of equilibrium distribution with different temperatures. These temperatures characterizing the tails are dependent on a characteristic length in which a memory of dynamics is completely erased by several particle collisions. This property of the tails of nonequilibrium distribution is confirmed in other thermal transport systems. In addition, statistical properties of a particle trapped by a harmonic potential in a steady thermal conducting state are also studied. This particle feels a finite force parallel to the average thermal current as a consequence of the skewness of the distribution of the current. This force is interpreted as the microscopic origin of thermophoresis.
Yukawa S, Ogushi F, Shimada T, Ito N (2010) Nonequilibrium Distribution of the Microscopic Thermal Current in Steady Thermal Transport Systems. Progress of Theoretical Physics Supplement 184: 415–428. Available: http://dx.doi.org/10.1143/ptps.184.415.
This work was partly supported by a Grant-in-Aid for Scientific Research (B)No. 19340110, a Grant-in-Aid for Young Scientists (B) No. 19740238 from the MinistryEducation, Culture, Sports, Science and Technology Japan, and the GlobalResearch Partnership of King Abdullah University of Science and Technology (KUKI1-005-04).