CAJ | 학술논문

The transport properties in a kind of simple system are studied within the framework of a generalized Frenkel-Kontorova model where the chain is comp osed of two kinds of atoms. Its studied mobility includes two aspects: the velo city m obility Bv and the momentum mobility Bm. The effective system temp eratures for t he two subchains, Te1 and Te2 are defined, respectively. For t he underdamped ca se, the regime of nonlinear response becomes wider and more "steps" occur when t he value of mincreases. For m= 1, Te1(F) = Te2(F). For m>1, Te1(F) > Te2(F) an d the difference increases with the increase of m. The momentum transportati on s hows very different behavior from that of the velocity transportation. Within a prescribed intermediate "steps" of Bv(F) or Bm(F), both of them decr ease with the increase of F and Bm(F) decreases more quickly. For the case of over damping an d nonzero temperature, the hysteresis interval becomes thinner and the transitions become smoother. The increase of m makes the hysteresis thinner and the t rans itions smoother. When T is high, all the transitions are smeared out, and th e di atomic effects become unimportant. We expect these results contribute to the und erstanding of the atomic processes occurring at the interface of two materials w hen they are brought together and moved with respect to one another.